Liquid sensors for substrate processing systems

Abstract

A sensor includes a first layer of a first insulating material, a second layer including a grid of wires, and a third layer including a mesh of a second insulating material arranged on the second layer. The wires include insulated conductors arranged on the first layer. The grid of wires includes first wires arranged along a first axis, second wires arranged along a second axis intersecting the first axis, and third wires arranged along the first axis. Portions of the first, second, and third wires are partially uninsulated to partially expose respective conductors in regions where the first, second, and third wires intersect. Partially insulated portions of the first, second, and third wires where the first, second, and third wires intersect lie between the partially exposed respective conductors.

Description

LIQUID SENSORS FOR SUBSTRATE PROCESSING SYSTEMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 662,545, filed on June 21 , 2024. The entire disclosure of the application referenced above is incorporated herein by reference.FIELD

[0002] The present disclosure relates generally to substrate processing systems and more particularly to liquid sensors for sensing leaks in substrate processing systems.BACKGROUND

[0003] The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] Substrate processing systems are used to treat substrates such as semiconductor wafers. A substrate processing system (also called a tool) comprises a processing chamber. The processing chamber comprises a plurality of process modules (also called stations). Each station can process a substrate. For example, the processing may include deposition, etching, cleaning, and / or other substrate treatments. During processing, the substrate is arranged on a substrate support in the station. A gas delivery system introduces one or more gases into the station via a gas delivery device. For example, the gas delivery device can be a showerhead, an injector, and so on. In some processes, plasma may be used to initiate chemical reactions.SUMMARY

[0005] A sensor comprises a first layer of a first insulating material, a second layer comprising a grid of wires, and a third layer comprising a mesh of a second insulating material arranged on the second layer. The wires comprise insulated conductors arranged on the first layer. The grid of wires comprises first wires arranged along a first axis, second wires arranged along a second axis intersecting the first axis, and third wires arranged along the first axis. Portions of the first, second, and third wires are partiallyuninsulated to partially expose respective conductors in regions where the first, second, and third wires intersect. Partially insulated portions of the first, second, and third wires where the first, second, and third wires intersect lie between the partially exposed respective conductors.

[0006] In additional features, the first wires and third wires are equal in number. Each of the first wires is adjacent to a corresponding one of the third wires.

[0007] In additional features, each of the third wires is configured to receive a signal. The signal from one of the third wires is coupled to one of the first wires and one of the second wires that intersect the one of the third wires in response to a liquid flowing through the mesh in the third layer into one of the regions of the second layer and contacting the one of the third wires in the one of the regions.

[0008] In additional features, a system comprises the sensor and further comprises a controller connected to the grid of wires in the second layer. The controller is configured to supply the signal to the third wires, receive signals through one of the first wires and one of the second wires in response to the liquid contacting the one of the third wires in the one of the regions, and detect presence of the liquid in the one of the regions based on the signals.

[0009] In additional features, the third layer comprises a layer of a salt that ionizes the liquid flowing through the mesh in the third layer into the second layer.

[0010] In additional features, the grid of wires in the second layer is divided into a plurality of zones. Each zone of the plurality of zones comprises two or more wires of at least one of (i) the first wires and (ii) the second wires.

[0011] In additional features, a system comprises the sensor and further comprises a controller connected to the grid of wires in the second layer. The controller is configured to supply a signal to the third wires, receive signals through one of the first wires and one of the second wires in one of the plurality of zones in response to a liquid flowing through the mesh in the third layer and contacting one of the third wires in one of the plurality of zones, and detect presence of the liquid in the one of the plurality of zones based on the signals.

[0012] In additional features, a system comprises a plurality of the sensor. A first sensor of the plurality of the sensor is arranged at a first location of a path through which a liquid flows. A second sensor of the plurality of the sensor is arranged at a second location ofthe path downstream from the first location. The system further comprises a controller connected to the grid of wires in the second layer of each of the first sensor and the second sensor. The controller is configured to supply a signal to the third wires of each of the first sensor and the second sensor. The controller is configured to receive a first set of signals from the first wires and the second wires of the first sensor and a second set of signals from the second sensor in response the liquid following through the path, through the mesh in the third layer into the second layer of each of the first sensor and the second sensor, and contacting the third wires of each of the first sensor and the second sensor. The controller is configured to detect a change in a property of the liquid based on the first set of signals and the second set of signals.

[0013] In additional features, the system further comprises a first fitting and a second fitting. The first sensor is arranged in the first fitting. The second sensor is arranged in the second fitting.

[0014] In additional features, a system comprises a fitting configured to flow a liquid therethrough, the sensor arranged around the fitting, and a controller connected to the grid of wires in the second layer of the sensor. The controller is configured to supply a signal to the third wires. The controller is configured to receive signals through the one of the first wires and the one of the second wires in response to the liquid leaking from the fitting, flowing through the mesh in the third layer into one of the regions of the second layer, and contacting one of the third wires in the one of the regions of the second layer of the sensor. The controller is configured to detect presence of the liquid in the one of the regions of the second layer based on the signals.

[0015] In additional features, the fitting comprises an indicator arranged on the fitting, and the controller is connected to the indicator and is configured to activate the indicator to indicate the liquid leaking from the fitting.

[0016] In additional features, a system comprises a plurality of the sensor arranged in a roll that is wrapped around a component configured to flow a liquid therethrough. The system further comprises a controller configured to supply a signal to the third wires of each of the plurality of the sensor. The controller is configured to receive signals from one of the first wires and one of the second wires of one of the plurality of the sensor in response to the liquid leaking from the component, flowing through the mesh in the third layer into one of the regions of the second layer of the one of the plurality of the sensor, and contacting one of the third wires in the one of the regions of the one of the pluralityof the sensor. The controller is configured to detect presence of the liquid in one of the regions of the one of the plurality of the sensor based on the signals.

[0017] In additional features, a system comprises a plurality of the sensor arrange on an inner wall of a container configured to contain a liquid. The system further comprises a controller configured to supply a signal to the third wires of each of the plurality of the sensor. The controller is configured to receive signals from one of the first wires and one of the second wires of one of the plurality of the sensor in response to the liquid flowing through the mesh in the third layer into one of the regions of the second layer of the one of the plurality of the sensor, and contacting one of the third wires in the one of the regions of the one of the plurality of the sensor. The controller is configured to detect presence of the liquid in one of the regions of the one of the plurality of the sensor based on the signals. The controller is configured to detect a level of the liquid in the container based on detecting presence of the liquid in the one of the regions of the second layer of the one of the plurality of the sensor.

[0018] In additional features, a system comprises the sensor arranged on a surface of a component comprising a plurality cutout areas on the surface. The sensor is aligned with the surface of the component and comprises cutouts aligned with the cutout areas on the surface of the component. The grid of wires in the second layer of the sensor comprises discontinuities in the first, second, and third wires in the cutouts. The first wires and the third wires are collected from a first side of the sensor and are connected to a controller. The second wires are collected from a second side of the sensor and are connected to the controller.

[0019] In additional features, the first wires and the third wires are collected from a third side of the sensor and are connected to the controller, and the third side is opposite to the first side.

[0020] In additional features, the second wires are collected from a fourth side of the sensor and are connected to the controller, and the fourth side is opposite to the second side.

[0021] In additional features, the system further comprises the controller configured to supply a signal to the third wires. The controller is configured to receive signals through one of the first wires and one of the second wires in response to a liquid leaking on the surface of the component, flowing through the mesh in the third layer into one of the regions of the second layer, and contacting one of the third wires in the one of the regionsof the second layer. The controller is configured to detect presence of the liquid in the one of the regions of the second layer based on the signals.

[0022] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0024] FIGS. 1A and 1 B show examples of substrate processing systems (tools) in which a leak detection sensor of the present disclosure can be used to detect a leak and / or detect a change in a property of a liquid in a flow path of the liquid;

[0025] FIGS. 2-4 show an example of the leak detection sensor;

[0026] FIGS. 5-7 show examples of different ways of packaging the leak detection sensor;

[0027] FIGS. 8-11 C show examples of various cross-sections of wires used in the leak detection sensor;

[0028] FIGS. 12-15 show examples of forming zones in the leak detection sensor and an example of a controller that detects a leak and a change in a property of the liquid using the leak detection sensor; and

[0029] FIGS. 16A-21 B show various examples of applications (use cases) in which the leak detection sensors can be used in the tools.

[0030] In the drawings, reference numbers may be reused to identify similar and / or identical elements.DETAILED DESCRIPTION

[0031] In substrate processing systems (tools), liquids are often used to perform processes (e.g., deposition, etching, and cleaning) and to cool various components of the tools. Non-limiting examples of liquids used in processes comprise liquid precursors and other liquids that are converted into gaseous phase and supplied to a processing chamber for processing substrates. Cooling systems use liquids as coolants to controltemperatures of various components of the tool. For example, the cooling systems may supply liquids through cooling channels and / or manifolds disposed in and / or around the components to control the temperatures of the components. Non-limiting examples of components of which temperatures are controlled by the cooling systems comprise pedestals, showerheads, dielectric windows, power supplies, and other components. The cooling systems may use a variety of liquids as coolants that are circulated through the cooling channels in or around the components. Non-limiting examples of the liquids comprise water and other chemicals. In addition, liquids are used during wet processes performed on substrates. Examples of wet processes include wet cleaning of substrates, wet etching processes performed on substrates, etc. Some of the liquids used in the processes and the cooling systems may be electrically conducting while others may not be good conductors of electricity. Some of the liquids can be corrosive and / or otherwise hazardous to the health.

[0032] Sometimes, the conduits carrying the liquid and / or other fixtures associated with the conduits carrying the liquid can deteriorate or malfunction and can leak. The leaking liquid can damage a component of the tool. For example, the leaking liquid can cause a short circuit, corrode a component of the tool, and so on. The leaking liquid can also pose a health hazard to a service technician diagnosing and fixing the leak. Accordingly, it is desirable to detect a leak early and also to detect the location of the leak so that the cause of the leak can be quickly isolated and fixed.

[0033] Many leak detection sensors are used to detect leaks in tools. However, these sensors have many drawbacks. Specifically, the leak sensors that are currently used to detect leaks in the tools are generically designed for detecting leaks in domestic appliances and industrial equipment, which are different than the tools used to manufacture semiconductors. Further, these sensors need to be immersed partially or fully in liquid before a leak can be detected. For example, some sensors can detect a leak only after the liquid accumulates to a particular level. However, the leaking liquid can cause damage before the liquid accumulates to a particular level and the leak can be detected. Accordingly, these sensors are fraught with delayed leak detection since the sensors cannot detect a leak until the sensors are properly and sufficiently immersed in the leaking liquid. The sensors are also prone to electrical noise, which can degrade their performance and cause false tripping and alarms. As such, these sensors are unsuitable for use in semiconductor processing equipment, particularly in regions where the leaking liquid can flow freely and spread to other regions of the tool, since the free-flowing liquidcan be hazardous and can cause severe damage to the tool before the leak can be detected using these sensors.

[0034] Most sensors also cannot detect the location where a leak is occurring. Detecting where the leak is occurring can take time, which can not only damage the tool but can also endanger the health and safety of the service technician diagnosing and fixing the leak. Some sensors cannot be deployed in certain locations (e.g., on or around components) due to mounting difficulties, inability to meet other requirements of the sensors to function, and so on.

[0035] The present disclosure provides a leak detection sensor that solves the above problems and that can perform additional functions that the current sensors cannot perform. The leak detection sensor can not only detect leaks when they occur (i.e., without requiring a particular liquid level) but can also detect the location where a leak is occurring. The leak detection sensor can detect a leak when a single drop of a liquid falls on the sensor or when just a few (e.g., 2-3) drops of a liquid fall on the sensor. The leak detection sensor can detect a leak within seconds (e.g., 2-3 seconds) of the leak occurring. The sensitivity of the leak detection sensor can be adjusted by adjusting detection thresholds. The leak detection sensor is immune to electrical noise due to its meshed architecture, which is described below in detail.

[0036] Additionally, unlike the current leak detection sensors, the leak detection sensor of the present disclosure can be used to detect changes in a property of the liquid (e.g., concentration, conductivity, and so on) as described below in detail. The leak detection sensor can also be used to detect liquid level in a container (e.g., level of a liquid precursor being vaporized for use in a process). Further, the leak detection sensor can be manufactured in any size and shape and can be deployed anywhere in the tool. The leak detection sensor can be customized to meet specific requirements of each tool. The leak detection sensor can provide data for equipment intelligence which existing sensors cannot provide due to their architectural limitations. The leak detection sensor can send data about leak detection (e.g., location of the leak) and about change in a property (e.g., concentration) of a liquid to the tool controller. In some implementations, a leak detection indication (e.g., in the form of an LED) can be provided proximate to the location of the leak detection senor to facilitate quick service.

[0037] Specifically, as described below in detail, the leak detection sensor is flexible in form. The leak detection sensor comprises a mesh of wires (conductors). The leakdetection sensor can be sized, shaped, and deployed in many ways. For example, the leak detection sensor can be made in the form of a sheet or a mat that can be placed anywhere in the tool (e.g., on the tool floor, on top of a power supply, and so on). The leak detection sensor can be built in the form of small pads and can be placed directly under locations where a leak may occur (e.g., under junctions of conduits, locations where conduits connect to other components, and so on). The leak detection sensor can also be placed in drip trays and enclosures used in tools.

[0038] The leak detection sensor can be built in the form of a roll that can be cut to required size and shape like an adhesive tape, which can then be placed (stuck) at locations where a leak is likely to occur (e.g., under and / or around a conduit that can corrode over time and cause a leak). The leak detection sensor can be wrapped around a component (e.g., a conduit carrying the liquid). The leak detection sensor can also be used to detect a liquid level in a container. For example, the roll comprising the leak detection sensors arranged at predetermined locations can be installed vertically along an inner wall of the container. As the liquid level changes, the leak detection sensors can detect the liquid level in the container.

[0039] The leak detection sensor can be fabricated in the form of a cover that can be placed on top of liquid fittings. The leak detection sensor can act as a temporary seal at a connection point, where a small amount of leak can be contained within the cover and can also be detected quickly. Further, a leak indication (e.g., an LED) can be provided on the fitting itself to facilitate service.

[0040] The leak detection sensor can be fabricated in the form of fittings (couplings) that can be installed in a path of liquid flow. For example, the leak detection sensor can be installed along an inner wall of a conduit (e.g., as a liner) through which a liquid flows or should not flow. The leak detection sensor can determine presence or absence of liquid flow. Using the liner type deployment of the leak detection sensor, multiple leak detection sensors can be installed across a liquid flow path. For example, a first leak detection sensor can be located at an input point before a liquid enters into a processing chamber, and a second leak detection sensor can be located at an output point after the liquid exits the processing chamber. Using this type of deployment of the leak detection sensors in the path of liquid flow, a change in a property such as concentration of the liquid can be detected across the flow path. For example, a change in concentration may cause a change in electrical conductivity of the liquid. The change is reflected in terms of changesin voltages of the second leak detection sensor at the output point relative to the voltages of the first leak detection sensor at the input point. The detected change can be communicated to the tool controller to perform relevant actions. For example, the actions may comprise stopping the flow of the liquid, purifying the liquid, and so on.

[0041] The leak detection sensor can be built in the form of a sheet that can be used with assemblies such as power supplies that have cutouts (e.g., to connect bulkheads to an assembly). The wires in the mesh of the leak detection sensor can be routed around the cutouts in the assembly such that areas in the leak detection sensor can be cutout to align with the cutouts in the assembly without creating discontinuities in the mesh. Alternatively, as described below in detail, areas in the leak detection sensor can be cutout to align with the cutouts in the assembly. To account for the discontinuities in the mesh created by the cutouts in the leak detection sensor, wires from two or more sides of a cutout area in the leak detection sensor can be utilized to sense leaks despite the discontinuities in the mesh. Some assemblies may have cutouts on top and / or bottom. The leak detection sensor with areas (without or with the discontinuities in the mesh) that match the cutouts of an assembly can be placed on top of the assembly having cutouts. For an assembly having cutouts at the bottom of the assembly, the leak detection sensor with areas (without or with the discontinuities in the mesh) that match the cutouts of the assembly can be placed on the bottom of the assembly, and components of the assembly can be built on top of the leak detection sensor.

[0042] Furthermore, the leak detection sensor is scalable in size. The size of the mesh can be increased by extending the wires in the mesh and / or adding more wires to the mesh to meet sensing needs. The size of the leak detection sensor can be decreased by shortening the wires in the mesh and / or reducing the number of wires in the mesh to meet sensing needs.

[0043] The leak detection sensor can be configured to detect the location of a leak with varying resolution. For example, as described below in detail, the leak detection sensor can pinpoint the location of a leak depending where a drop of liquid contacts the sensor. The leak detection sensor can also be divided into zones by grouping some of the wires in the mesh. When zoned, the leak detection sensor can detect a leak in a zone. The size of the zone can be changed to change the resolution with which the leak detection sensor can detect the location of a leak. For example, the zones can be larger where a leak is less likely to occur and can be smaller where leaks are more likely to occur.

[0044] The leak detection sensor is not limited to detecting leaks of electrically conducting liquids such as water. The leak detection sensor can detect any sufficiently electrically conductive liquid. The leak detection sensor can also detect leaks of electrically non-conducting liquids (e.g., deionized water and other chemicals). To facilitate leak detection of electrically non-conducting liquid, a salt that ionizes the electrically non-conducting liquid may be deposited on top of the mesh (e.g., in a layer on top of the mesh of conductors as described below). The ionization increases the electrical conductivity of the liquid that contacts the leak detection sensor so that the leak detection sensor can detect a leak. These and other features of the leak detection sensor of the present disclosure are described below in detail.ORGANIZATION

[0045] The present disclosure is organized as follows. Examples of tools in which the leak detection sensor can be used are shown and described with reference to FIGS. 1 A and 1 B. An example of the leak detection sensor of the present disclosure is shown and described with reference to FIGS. 2-4. Examples of different ways of packaging the leak detection sensor are shown and described with reference to FIGS. 5-7. Examples of various cross-sections of the wires used in the leak detection sensor are shown and described with reference to FIGS. 8-1 1 C. Examples of forming zones in the leak detection sensor and an example of a controller that detects a leak and a change in a property of the liquid using the leak detection sensor are shown and described with reference to FIGS. 12-15. Examples of various applications (use cases) in which the leak detection sensor can be used are shown and described with reference to FIGS. 16A-21 B.EXAMPLES OF TOOLS

[0046] FIG. 1 A shows an example of a substrate processing system (tool) 100. The tool 100 comprises a plurality of stations 102-1 , 102-2, 102-3, 102-4 (collectively called the stations 102). While four stations 102 are shown as an example, the tool 100 can comprise any number of stations. For example, the stations 102 may be arranged in two rows, where each row can comprise four stations.

[0047] Each station 102 comprises a pedestal and a showerhead. The pedestals in the stations 102 are shown at 104-1 , 104-2, 104-3, 104-4 (collectively called the pedestals 104 and individually called the pedestal 104). The showerheads in the stations 102 are shown at 106-1 , 106-2, 106-3, 106-4 (collectively called the showerheads 106 and individually called the showerhead 106).

[0048] Each station 102 has a gas box and a RF power supply associated with the station 102. The gas boxes are shown at 1 10-1 , 1 10-2, 110-3, 1 10-4 (collectively called the gas boxes 1 10 and individually called the gas box 1 10). The RF power supplies are shown at 112-1 , 1 12-2, 1 12-3, 1 12-4 (collectively called the RF power supplies 1 12 and individually called the RF power supply 1 12). Optionally, each station 102 also has a delivery system associated with the station 102 to deliver one or more vaporized precursors to the station 102. The delivery systems are shown as Vap. Prec. at 114-1 , 1 14-2, 1 14-3, 1 14-4 (collectively called the VP delivery systems 1 14 and individually called the VP delivery system 1 14). The gas boxes 110, the RF power supplies 1 12, and the VP delivery systems 1 14 may be arranged on a top plate 103 of the tool 100 that lies above the stations 102.

[0049] During processing, a substrate (not shown) is placed on the pedestal 104 in the station 102. The gas box 110 supplies one or more process gases to the showerhead 106 in the station 102. Optionally, the VP delivery system 114 may also supply one or more vaporized precursors to the showerhead 106 in the station 102. To process the substrate in the station 102, the RF power supply 1 12 supplies RF power to the station 102 (e.g., to the showerhead 106 in the station 102). The RF power ignites a gas mixture in the station 102, which strikes plasma between the showerhead 106 and the pedestal 104 in the station 102.

[0050] The tool 100 also comprises a cooling system 120 that supplies one or more coolants (e.g., liquids) to cool components such as the pedestals 104 and the RF power supplies 1 12. For example, a cooling manifold 122 is arranged under the pedestals 104 (under the stations 102). The cooling system 120 supplies the coolant to the cooling manifold 122. The coolant circulated through the cooling manifold 122 cools the pedestals 104. Optionally, while not shown, the cooling system 120 may also supply the coolant to the showerheads 106. The cooling system 120 may also supply the coolants through various other conduits and manifolds (not shown) to the RF power supply 1 12, the showerheads 106, and many other components of the tool 100 (e.g., components located on the top plate 103 and elsewhere in the tool 100). The conduits and manifolds are routed through many regions of the tool 100 in which many other components of the tool 100 may be located.

[0051] The conduits and manifolds comprise various couplings and fittings that facilitate routing of the conduits and manifolds around the components in the tool 100. Sometimes,conduits and manifolds can leak. For example, the conduits and manifolds can wear (e.g., corrode due to the liquids flowing through them). The couplings and fittings can also wear or become loose over time. The liquids leaking from these elements can damage the components of the tool 1 10 and cause other problems described above. The leak detection sensors of the present disclosure can be placed proximate and / or around to these elements and in various regions of the tool 100 to detect these leaks as described below in detail.

[0052] The leak detection sensors communicate with a system controller 130, which controls the operations of the various components and subsystems of the tool 100. Upon detection of a leak, the system controller 130 can perform a suitable action. For example, the system controller 130 can shut down a portion of the cooling system 120 supplying the coolant to where the leak is detected. The system controller 130 can shut down the component where the leak is detected. The system controller 130 can generate an alarm to alert an operator of the tool that a leak is detected so that the operator can perform a corrective action. For example, the corrective action can include the actions described above and optionally include scheduling service for the tool 100.

[0053] FIG. 1 B shows another example of a substrate processing system (tool) 200. The tool 200 comprises a plurality of stations 202-1 , 202-2, 202-3, 202-4 (collectively called the stations 202). While four stations 202 are shown as an example, the tool 200 can comprise any number of stations. For example, the stations 202 may be arranged in two rows, where each row can comprise four stations.

[0054] Each station 202 comprises a pedestal. The pedestals in the stations 202 are shown at 204-1 , 204-2, 204-3, 204-4 (collectively called the pedestals 204 and individually called the pedestal 204). Each station 202 comprises a dielectric window arranged above the pedestals 204. The dielectric windows of the stations 202 are shown at 206-1 , 206-2, 206-3, 206-4 (collectively called the dielectric windows 206 and individually called the dielectric window 206). One or more coils are arranged above the dielectric windows 206. The coils are shown at 208-1 , 208-2, 208-3, 208-4 (collectively called the coils 208 and individually called the coil 208). A gas injector is located in the dielectric window 206 of each station 202. The gas injectors are shown at 209-1 , 209-2, 209-3, 209-4 (collectively called the gas injectors 209 and individually called the gas injector 209).

[0055] Each station 202 has a gas box and a RF power supply associated with the station 202. The gas boxes are shown at 210-1 , 210-2, 210-3, 210-4 (collectively called the gas boxes 210 and individually called the gas box 210). The RF power supplies are shown at 212-1 , 212-2, 212-3, 212-4 (collectively called the RF power supplies 212 and individually called the RF power supply 212). The gas boxes 210, the RF power supplies 212, and the VP delivery systems 1 14 may be arranged on a top plate 203 of the tool 200 that lies above the stations 202.

[0056] During processing, a substrate (not shown) is placed on the pedestal 204 in the station 202. The gas box 210 supplies one or more process gases to the gas injector 209 in the station 202. To process the substrate in the station 202, the RF power supply 212 supplies RF power to the station 202 (e.g., to the coil 208 above the dielectric window 206 above the station 202). The RF power ignites a gas mixture in the station 202, which strikes plasma between the gas injector 209 and the pedestal 204 in the station 202. A bias power supply located under each station 202 supplies RF bias to the pedestal 204 in the station 202. The bias power supplies are shown at 214-1 , 214-2, 214-3, 214-4 (collectively called the bias power supplies 214 and individually called the bias power supply 214).

[0057] The tool 200 also comprises a cooling system 220 that supplies one or more coolants (e.g., liquids) to cool components such as the pedestals 204 and the RF power supplies 212. For example, a cooling manifold 222 is arranged under the pedestals 204 (under the stations 202). The cooling system 220 supplies the coolant to the cooling manifold 222. The coolant circulated through the cooling manifold 222 cools the pedestals 204. The bias power supplies 214 are located under the cooling manifold 222. The cooling system 120 may also supply the coolants through various other conduits and manifolds (not shown) to the RF power supplies 212, dielectric windows 206, the bias power supplies 214, and many other components of the tool 100 (e.g., components located on the top plate 203 and elsewhere in the tool 100). The conduits and manifolds are routed through many regions of the tool 200 in which many other components of the tool 200 may be located.

[0058] The conduits and manifolds comprise various couplings and fittings that facilitate routing of the conduits and manifolds around the components in the tool 200. Sometimes, conduits and manifolds can leak. For example, the conduits and manifolds can wear (e.g., corrode due to the liquids flowing through them). The couplings and fittings can also wearor become loose over time. The liquids leaking from these elements can damage the components of the tool 200 and cause other problems described above. The leak detection sensors of the present disclosure can be placed proximate and / or around to these elements and in various regions of the tool 200 to detect these leaks as described below in detail.

[0059] The leak detection sensors communicate with a system controller 230, which controls the operations of the various components and subsystems of the tool 200. Upon detection of a leak, the system controller 230 can perform a suitable action. For example, the system controller 230 can shut down a portion of the cooling system 220 supplying the coolant to where the leak is detected. The system controller 230 can shut down the component where the leak is detected. The system controller 230 can generate an alarm to alert an operator of the tool that a leak is detected so that the operator can perform a corrective action. For example, the corrective action can include the actions described above and optionally include scheduling service for the tool 200.

[0060] In addition, while not shown, the tools 100, 200 may comprise additional station(s) in which one or more wet processes (e.g., wet cleaning, wet etching, etc.) may be performed on substrates using one or more liquids. The leak detection sensors of the present disclosure can also be used to detect leaks and to detect changes in properties of the liquids (described below) used in the wet processes.

[0061] While the examples provided above generally include multi-station chambers, other implementations may include single-station chambers. Further, in some examples, various features of the tools (e.g., RF power supply, etc.) may be omitted. The leak detection sensors of the present disclosure can also be used with stations configured for wet processing.EXAMPLES OF SENSOR

[0062] FIGS. 2-4 show a leak detection sensor 300 of the present disclosure. FIGS. 5- 7 show examples of different ways of packaging the leak detection sensor 300. FIGS. 8- 10 and 1 1 A-1 1 C show various cross-sections of the leak detection sensor 300. FIGS. 12- 15 show various sensing schemes that can be used with the leak detection sensor 300. FIGS. 16A-15C, 17-19, and 20A-20C show various applications (use cases) of the leak detection sensor 300. The leak detection sensor 300 can be used in the tools 100, 200 (and other tools).

[0063] In FIGS. 2-4, the leak detection sensor 300 is shown in detail. FIG. 2 schematically shows the leak detection sensor 300. The leak detection sensor 300 comprises three layers that are bonded together. A first layer (base layer) 302 is an insulation layer. The first layer 302 comprises a material that is thermally, electrically, and chemically resistant. That is, the material of the first layer 302 is thermally and electrically insulating and is also resistant to chemicals. For example, the material does not disintegrate, degenerate, or degrade when the material is exposed to heat and electricity, and when the material comes in contact with liquids that leak in the tools. The first layer 302 is also called a base insulation layer (or a first insulation layer) 302.

[0064] A second layer 304 is disposed on the first layer 302 and comprises a grid (mesh) of insulated wires. The second layer 304 is described below in detail with reference to FIG. 4. The second layer 304 is a sensing layer of the leak detection sensor 300 that senses (detects) the leaks and that can perform other functions (e.g., detecting a change in a property of a liquid in a flow path of the liquid and deleting a level of a liquid in a liquid container) as described below in detail with reference to subsequent figures.

[0065] A third layer 306 is disposed on the second layer 304 and is also an insulation layer. The third layer 306 also comprises a material that is thermally, electrically, and chemically resistant. The material of the third layer 306 may be the same or different than the material of the first layer 302 but has similar properties as the material of the first layer 302. The second layer 304 is arranged (sandwiched) between the third layer 306 and the first layer 302.

[0066] As shown in FIG. 3, unlike the first layer 302, the third layer 306 is meshed. The meshed configuration of the third layer 306 allows a liquid that falls on the third layer 306 to trickle down to the second layer 304, which senses the leak and performs other functions as described below in detail. The third layer 306 is also called a meshed insulation layer (or a second insulation layer) 306.

[0067] To detect a liquid in a leak that is not electrically conducting (or that has a low electrical conductivity), a layer of an ionizing compound (e.g., NaCI, KNO3, KCIO3, NaPO4, etc.) 308 is deposited in the third layer 306. In general, the ionizing compounds are also collectively called the salts 308 and individually called the salt 308. As the liquid comes in contact with the third layer 306, the salt 308 in the third layer 306 ionizes the liquid. The ionized liquid, which is electrically conducting due the presence of the ions inthe ionized liquid, trickles down to the second layer 304, which can sense the leak as described below in detail.

[0068] FIG. 4 shows the second layer 304 of the leak detection sensor 300 in detail. The second layer 304 comprises a grid or mesh of wires. The wires comprise conductors that are electrically insulated except at intersections as described below in detail with reference to FIGS. 8-1 1 C. Specifically, the second layer 304 comprises three sets of wires. For example, the three sets of wires are arranged along x and y axes as shown. The wires need not be perpendicular as shown. The wires in the three sets can be woven in any manner. For convenience, a first set of wires that lie along the x-axis are called x1 , x2, x3, and so on; and a second set of wires that lie along the y-axis are called y1 , y2, y3, and so on. The first set of wires are collectively called the x wires, and the second set of wires are collectively called the y wires. Any number of x and y wires can be used. An electrical signal is not externally supplied to the x and y wires. The x and y wires sense the leak as described below in detail with reference to FIGS. 8-15.

[0069] A third set of wires shown as v are externally supplied with an electrical signal (e.g., by a controller 400 shown and described below with reference to FIGS. 12-15) that is used to sense a leak as described below. The third set of wires are collectively called the v wires. The v wires can be arranged along the x axis as shown or along the y axis. When arranged along the x axis, one v wire is arranged adjacent to each x wire. When arranged along the y axis, one v wire is arranged adjacent to each y wire.

[0070] In FIG. 4, an example of an intersection of the x, y, and v wires is shown by a dotted circle. The details of the intersection are shown and described below in detail with reference to FIGS. 8-10 and 1 1 A-1 1 C. Briefly, at each intersection, the insulation of the x wire, the y wire, and the v wire is partially removed. The insulation is partially removed only at or near the points of intersection of the x, y, and v wires. The insulation is partially removed such that the conductors of the x, y, and v wires are partially exposed (i.e., are partially uninsulated) but the conductors of the x, y, and v wires do not contact each other.

[0071] When a drop of a liquid falls on the first layer 302 of the leak detection sensor 300, the drop trickles down through the mesh in the first layer 302 into the second layer 304. The drop contacts the partially exposed portions of the conductors of the x, y, and v wires at the intersection. Consequently, at the intersection where the drop of liquid falls, the conductors of the x and y wires connect to the v wire. That is, the drop of the liquid connects the conductors of the x, y, and v wires to each other. Consequently, theelectrical signal supplied to the v wire flows into the x and y wires. The controller (shown and described below with reference to FIGS. 12-15) senses the electrical signal on the x and y wires and detects the leak. In addition, depending on which x wire and which y wire gets connected to the v wire due to the drop of liquid falling on the intersection, the controller also identifies the location of the leak. The controller identifies the location of the leak in terms of X and Y coordinates of the intersection of x and y wires where the drop of liquid falls as described below in detail with reference to FIGS. 12-15.

[0072] FIGS. 5-7 show examples of different ways in which the leak detection sensor 300 can be packaged. In FIG. 5, the x, y, and v wires of the second layer 304 of the leak detection sensor 300 are grouped together and are connected to an external connector 350. The external connector 350 is connected to the controller 400 shown and described below with reference to FIGS. 12-15. The packaging shown in FIG. 5 can be used when the leak detection sensor 300 is deployed in the form of a mat or a pad (e.g., see FIGS. 16A-16C).

[0073] In FIG. 6, the connector 350 can be embedded in the leak detection sensor 300 itself and is external to (e.g., outside the footprint of) the leak detection sensor 300. In FIG. 7, the connector 350 can be embedded in the leak detection sensor 300 itself and is within the footprint of the leak detection sensor 300. The packaging shown in FIGS. 6 and 7 can be used when the leak detection sensor 300 is used in the form of a roll, a cover, and so on (e.g., see examples shown in FIGS. 17-19 and 20A-20C).

[0074] FIGS. 8-10 and 1 1 A-11 C show various cross-sections of the x, y, and v wires of the second layer 304 of the leak detection sensor 300 at an intersection of the x, y, and v wires (e.g., in the dotted circle shown in FIG. 4). The cross-sections are taken with the x, y, and v wires arranged as shown in FIG. 4. The cross-sections illustrate the partial removal of the insulation from the conductors of the x, y, and v wires at the intersection of the x, y, and v wires. While one intersection of the x, y, and v wires (e.g., in the dotted circle shown in FIG. 4) is described below, the following description applies to each intersection of the x, y, and v wires.

[0075] FIG. 8 shows a transverse section of each of the x, y, and v wires. The transverse section is taken along the length of each of the x, y, and v wires. Each of the x, y, and v wires comprises a conductor 360 surrounded by (encapsulated in) an insulating material 362. A portion of the insulating material 362 is removed to expose a portion of the conductor 360 as shown at 364 (called the exposed portion 364 of the conductor 360).The exposed portion 364 of the conductor 360 from which the insulating material 362 is removed to expose the portion of the conductor 360 is shown at 364 and is called the exposed portion 364 of the conductor 360. As shown and described below in detail with reference to FIGS. 9 and 10, for each of the x, y, and v wires, the exposed portion 364 of the conductor 360 lies diametrically opposite to the unexposed (insulated) portion of the conductor 360.

[0076] As explained below in detail, the regions of the x, y, and v wires from which the insulating material 362 is partially removed (i.e., the exposed portions 364 of the conductors 360 of the x, y, and v wires) lie at or near each intersection of the x, y, and v wires. Further, the x, y, and v wires are arranged (woven) in the mesh shown in FIG. 4 such that the exposed portions 364 of the conductors 360 of the x, y, and v wires do not contact each other. Rather, the unexposed (insulated) portion of the conductor 360 of a first wire, which is on the diametrically opposite side of the exposed portion 364 of the conductor 360 of the first wire, lies adjacent to and contacts the exposed portion 364 of the conductor 360 of a second wire, which prevents electrical contact between the exposed portions 364 of the conductors 360 of the first and second wires. For example, the first and second wires can be the following. When the x and v wires lie along the x axis and the y wires lie along the y axis as shown in FIG. 4, at the intersection in the dotted circle shown in FIG. 4, the first wire can be each of the x and v wires, and the second wire can be the y wire.

[0077] FIGS. 9 and 10 show examples of cross-sections of the x, y, and v wires taken along the x axis at the intersection in the dotted circle shown in FIG. 4. The cross-sections are taken with the x, y, and v wires arranged as shown in FIG. 4. In the examples shown in FIGS. 9 and 10, the y wire is above the x wire and under the v wire. In other examples, the y wire can be under the x wire and above the v wire.

[0078] In the examples shown in FIGS. 9 and 10, the conductors 360 of the x, y, and v wires are shown as 360-1 , 360-2, 360-3, respectively; the insulating materials 362 are shown as 362-1 , 362-2, 362-3, respectively; and the exposed portions 364 of the conductors 360 of the x, y, and v wires are shown as 364-1 , 364-2, 364-3, respectively.

[0079] In FIG. 9, the exposed portion 364-2 of the conductor 360-2 of the y wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-2 of the of the y wire. The exposed portion 364-1 of the conductor 360-1 of the x wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-1 of theof the x wire. The y wire lies above the x wire such that the unexposed (insulated) portion of the conductor 360-2 of the of the y wire lies above the exposed portion 364-1 of the conductor 360-1 of the x wire. Therefore, due to the intervening unexposed (insulated) portion of the conductor 360-2 of the of the y wire on the diametrically opposite side of the exposed portion 364-2 of the conductor 360-2 of the y wire, the exposed portion 364- 1 of the conductor 360-1 of the x wire does not contact the exposed portion 364-2 of the conductor 360-2 of the y wire.

[0080] In FIG. 10, the exposed portion 364-3 of the conductor 360-3 of the v wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-3 of the of the v wire. The exposed portion 364-2 of the conductor 360-2 of the y wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-2 of the of the y wire. The y wire lies under the v wire such that the unexposed (insulated) portion of the conductor 360-3 of the of the v wire, which is diametrically opposite to the exposed portion 364-3 of the conductor 360-3 of the v wire, lies above the exposed portion 364-2 of the conductor 360-2 of the y wire. Therefore, due to the intervening unexposed (insulated) portion of the conductor 360-3 of the of the v wire on the diametrically opposite side of the exposed portion 364-3 of the conductor 360-3 of the v wire, the exposed portion 364-2 of the conductor 360-2 of the y wire does not contact the exposed portion 364-3 of the conductor 360-3 of the v wire.

[0081] FIGS. 11 A-1 1 C show the insulated and uninsulated portions of the x, y, and v wires when the x, y, and v are arranged at the intersection in the dotted circle shown in FIG. 4. FIG. 1 1 A shows cross-sections of the x, y, and v wires taken along the y axis when the x, y, and v are arranged at the intersection in the dotted circle shown in FIG. 4. FIGS. 1 1 B and 1 1 C show cross-sections of the x, y, and v wires taken along the y axis when the x, y, and v are arranged differently than shown in FIG. 4.

[0082] In FIG. 1 1 A, the exposed portion 364-3 of the conductor 360-3 of the v wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-3 of the of the v wire. The exposed portion 364-2 of the conductor 360-2 of the y wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-2 of the of the y wire. The v wire lies above the y wire such that the unexposed (insulated) portion of the conductor 360-3 of the of the v wire, which is diametrically opposite to the exposed portion 364-3 of the conductor 360-3 of the v wire, lies above the exposed portion 364-2 of the conductor 360-2 of the y wire. Therefore, due to the intervening unexposed(insulated) portion of the conductor 360-3 of the of the v wire on the diametrically opposite side of the exposed portion 364-3 of the conductor 360-3 of the v wire, the exposed portion 364-2 of the conductor 360-2 of the y wire does not contact the exposed portion 364-3 of the conductor 360-3 of the v wire.

[0083] Additionally, the exposed portion 364-1 of the conductor 360-1 of the x wire is diametrically opposite to the unexposed (insulated) portion of the conductor 360-1 of the of the x wire. The y wire lies above the x wire such that the unexposed (insulated) portion of the conductor 360-2 of the of the y wire lies above the exposed portion 364-1 of the conductor 360-1 of the x wire. Therefore, due to the intervening unexposed (insulated) portion of the conductor 360-2 of the of the y wire on the diametrically opposite side of the exposed portion 364-2 of the conductor 360-2 of the y wire, the exposed portion 364- 1 of the conductor 360-1 of the x wire does not contact the exposed portion 364-2 of the conductor 360-2 of the y wire.

[0084] When a drop of a leaking liquid falls on the third layer 306, the drop trickles through the mesh in the third layer 306 and falls at or near an intersection of the x, y, and v wires (e.g., the intersection shown in the dotted circle in FIG. 4) in the second layer 304. The drop falls on the exposed portions 364-3, 364-2, 364-1 of the conductors 360- 3, 360-2, 360-1 of the v, y, and x wires as shown in FIG. 11 A. The drop connects the conductor 360-3 of the v wire to the conductors 360-2, 360-1 of the y and x wires. The electrical signal of the v wire is conducted by the y and x wires. The controller (shown at 400 in FIGS. 12-15) senses the electrical signal on the y and x wires and detects the leak and also determines the location of the leak based on which y wire and which x wire conducts the electrical signal from the v wire.

[0085] FIG. 1 1 B shows cross-section of an intersection of the x, y, and v wires taken along the y axis when the x and v wires are arranged above the y wire at the intersection. Elements of the x, y, and v wires are already described above with reference to FIG. 1 1 A and are therefore not described again for brevity. The x wire lies above the y wire such that the unexposed (insulated) portion of the conductor 360-1 of the of the x wire, which is diametrically opposite to the exposed portion 364-1 of the conductor 360-1 of the x wire, lies above the exposed portion 364-2 of the conductor 360-2 of the y wire. The v wire lies above the y wire such that the unexposed (insulated) portion of the conductor 360-3 of the of the v wire, which is diametrically opposite to the exposed portion 364-3 of the conductor 360-3 of the v wire, lies above the exposed portion 364-2 of the conductor360-2 of the y wire. Due to the intervening unexposed (insulated) portions of the conductors 360-1 , 360-3 of the of the x and v wires on the diametrically opposite side of the exposed portions 364-1 , 364-3 of the conductors 360-1 , 360-3 of the x and v wires, the exposed portion 364-2 of the conductor 360-2 of the y wire does not contact the exposed portions 364-1 , 364-3 of the conductors 360-1 , 360-3 of the x and v.

[0086] When a drop of a leaking liquid falls on the third layer 306, the drop trickles through the mesh in the third layer 306 and falls at or near an intersection of the x, y, and v wires in the second layer 304. The drop falls on the exposed portions 364-3, 364-2, 364-1 of the conductors 360-3, 360-2, 360-1 of the v, y, and x wires as shown in FIG.I I B. The drop connects the conductor 360-3 of the v wire to the conductors 360-2, 360- 1 of the y and x wires. The electrical signal of the v wire is conducted by the y and x wires. The controller (shown at 400 in FIGS. 12-15) senses the electrical signal on the y and x wires and detects the leak and also determines the location of the leak based on which y wire and which x wire conducts the electrical signal from the v wire.

[0087] FIG. 1 1 C shows cross-section of an intersection of the x, y, and v wires taken along the y axis when the x and v wires are arranged under the y wire at the intersection. Elements of the x, y, and v wires are already described above with reference to FIG. 1 1 A and are therefore not described again for brevity. The x and v wires lies under the y wire such that the exposed portions 364-1 , 364-3 of the conductors 360-1 , 360-3 of the x and v wires lie under the unexposed (insulated) portion 362-2 of the conductor 360-2 of the y wire. Due to the intervening unexposed (insulated) portion 362-2 of the conductor 360-2 of the y wire on the diametrically opposite side of the exposed portion 364-2 the conductor 360-2 of the y wire, the exposed portion 364-2 of the conductor 360-2 of the y wire does not contact the exposed portions 364-1 , 364-3 of the conductors 360-1 , 360-3 of the x and v.

[0088] When a drop of a leaking liquid falls on the third layer 306, the drop trickles through the mesh in the third layer 306 and falls at or near an intersection of the x, y, and v wires in the second layer 304. The drop falls on the exposed portions 364-3, 364-2, 364-1 of the conductors 360-3, 360-2, 360-1 of the v, y, and x wires as shown in FIG.I I C. The drop connects the conductor 360-3 of the v wire to the conductors 360-2, 360- 1 of the y and x wires. The electrical signal of the v wire is conducted by the y and x wires. The controller (shown at 400 in FIGS. 12-15) senses the electrical signal on the y and xwires and detects the leak and also determines the location of the leak based on which y wire and which x wire conducts the electrical signal from the v wire.EXAMPLES OF SENSOR CONTROLLER

[0089] FIGS. 12-15 show different examples of sensor controllers (hereinafter simply called the controllers) that supply the electrical signal to the v wires of the leak detection sensor 300 and sense a leak based on the electrical signal conducted by the x and y wires when a drop of a liquid falls on the sensor as described above. The controllers also supply the electrical signal to the v wires of two of the leak detection sensor 300 and sense a change in a property of a liquid based on the electrical signal conducted by the x and y wires of the two leak detection sensors 300 as described below in detail. FIGS. 13-15 also show different ways of forming zones in the leak detection sensor 300.

[0090] FIG. 12 shows a controller 400. The leak detection sensor 300 is connected to the controller 400. The controller 400 is connected to the system controller of the tool (e.g., elements 130, 230 shown in FIGS. 1 A and 1 B). The controller 400 comprises a signal processor 402, a detection circuit 404, a communication circuit 406, and a voltage converter 408.

[0091] The system controller 130 / 230 is connected to the communication circuit 406 to receive data from the controller 400 and to transmit data to the controller 400. For example, the communication circuit 406 can comprise one or more transceivers to exchange data with the system controller 130 / 230. The transceivers can comprise any communication interface and protocol such as RS-232, Ethernet, controller area network (CAN), distributed input / distributed output (DI / DO), etc. For example, the system controller 130 / 230 can transmit one or more lookup tables and one or more thresholds (both described below) to the controller 400. The controller 400 uses the lookup tables and the thresholds to detect a leak and to perform other functions described below. The system controller 130 / 230 can change the thresholds to change the sensitivity (described below) of leak detection and other functions performed by the leak detection sensor 300.

[0092] The system controller 130 / 230 can typically supply power at 12 or 24 volts to the controller 400, which power is also used to power some of the circuits on the tool. The voltage converter 408 comprises a DC-to-DC converter that converts the higher voltage supplied by the system controller 130 / 230 (e.g., 12 or 24 volts) to a lower voltage (e.g., 5 volts). The voltage output by the voltage converter 408 (e.g., 5V) is supplied to the components of the controller 400. The voltage output by the voltage converter 408 (e.g.,5V) is also supplied to the v wires of the leak detection sensor 300. In general, the voltage converter 408 can be a power converter that converts power received from the system controller 130 / 230 to a level that is suitable for the components of the controller 400 and for the leak detection sensor 300.

[0093] In FIGS. 12-15, the v wires are shown thicker only for illustrative purposes (e.g., to easily distinguish the v wires from various other lines shown in FIGS. 12-15). The v wires are not thicker than the x and y wires. The x, y, and v wires are identical (e.g., of the same gauge).

[0094] The signal processor 402 is connected to the x and y wires of the leak detection sensor 300. When a drop of a leaking liquid falls on the leak detection sensor 300, the voltage output to the v wires is conducted by the x and y wires as described above. For example, if the drop of a leaking liquid falls on the leak detection sensor 300 in the region shown by the dotted circle, the 5V signal on the v wire is conducted by the x1 and y1 wires. The signal processor 402 processes the signals received on the x1 and y1 wires.

[0095] For example, the signal processor 402 comprises one or more filters that filter the signals received from the x and y wires to filter any noise that may be present in the signals received from the x and y wires. The signal processor 402 comprises one or more amplifiers that amplify the signals received from the x and y wires. The signal processor 402 comprises one or more analog-to-digital converters (ADCs) that convert the signals received from the x and y wires from analog to digital format. The signal processor 402 converts the signals received from the x and y wires from analog to digital format for leak detection. The signal processor 402 may or may not convert the signals received from the x and y wires from analog to digital format for detecting a change in a property of the liquid, which is described below. The signal processor 402 outputs data generated by processing the signals received from the x and y wires to the detection circuit 404.

[0096] The detection circuit 404 detects the leak based on the output of the signal processor 402. For example, depending on the electrical conductivity of a leaking liquid (with or without using the salt depending on the type of liquid as described below), the voltage level of the signals received by the signal processor 402 from the x and y wires may be different for different liquids. The detection circuit 404 can store one or more lookup tables (e.g., received from the system controller 130 / 230) that store pre-calibrated values of signal levels for different liquids. The detection circuit 404 uses the values as thresholds for detecting leaks of different liquids. When the leak detection sensor 300 isplaced in a region of the tool, the type of liquid that is likely to leak in the region is known. The controller 400 may store many lookup tables for many liquids used in the tool. The system controller 130 / 230 can program the controller 400 to select a lookup table for that liquid to detect a leak of the liquid in the region.

[0097] When the detection circuit 404 receives the output of the signal processor 402, the detection circuit 404 compares the output to the threshold for that liquid. If the output is greater than the threshold, a leak is detected. The sensitivity at which the leak detection sensor 300 can detect the leak can be increased or decreased by decreasing or increasing the threshold. For example, setting low thresholds (high sensitivity) can be useful in applications where no leak can be tolerated (e.g., when the liquid is hazardous or when the liquid is not hazardous but will cause severe damage to a component such as a power supply of the tool). For example, thresholds can be set high (low sensitivity) in applications where a small leak is tolerable (e.g., when the liquid is not hazardous and may not damage the tool or may evaporate in a short amount of time). Depending on where the leak detection sensor 300 is placed in a region of the tool, the type of liquid that is likely to leak in the region, and the desired sensitivity for leak detection, the controller 400 may store many lookup tables for many liquids used in the tool.

[0098] The output of the signal processor 402 also includes the location information of the leak. For example, in the above example, the leak is detected at the intersection of the x1 and y1 wires. That is the X and Y coordinates of the leak are (x1 , y1 ). The detection circuit 404 transmits data indicating the detection of the leak and the location of the detected leak through the communication circuit 406 to the system controller 130 / 230. The system controller 130 / 230 can perform suitable actions as described above (e.g., stopping one or more operations, generating an alarm, etc.).

[0099] In some examples, the leak detection sensor 300 and the controller 400 can also detect a change in property of a liquid. For example, when a liquid flows from point A to point B, electrical properties of the liquid may change due to changes in surrounding temperatures, a chemical reaction that the liquid is subjected or exposed to (e.g., a process being performed in the processing chamber), and so on (e.g., see an example shown in FIGS. 20A-20C). For example, an impurity may get added to the liquid during the use of the liquid. As a result, the concentration of the liquid may change. A change in purity and / or concentration changes the electrical conductivity of the liquid. The leakdetection sensor 300 and the controller 400 can detect the change in the electrical conductivity of the liquid using two leak detection sensors 300 as follows.

[0100] A first leak detection sensor 300 is placed at point A in the path of the liquid flow. A second first leak detection sensor 300 is placed at point B in the path of the liquid flow. The liquid flows the first and second first leak detection sensors 300. The x and y wires of the first leak detection sensor 300 provide a first set of voltages to the signal processor 402. The first set of voltages indicate the electrical conductivity of the liquid at point A. The x and y wires of the second leak detection sensor 300 provide a second set of voltages to the signal processor 402. The second set of voltages indicate the electrical conductivity of the liquid at point B.

[0101] The signal processor 402 processes the first and second sets of voltages and provides outputs to the detection circuit 404. If the electrical conductivity of the liquid has not changed by more than a predetermined calibrated amount, the detection circuit 404 provides an output indicating that the properties of the liquid are unchanged. If the electrical conductivity of the liquid has changed by more than the predetermined calibrated amount, the detection circuit 404 provides an output indicating that the properties of the liquid have changed. The detection circuit 404 transmits the detected result the through the communication circuit 406 to the system controller 130 / 230. The system controller 130 / 230 can perform suitable actions as described above (e.g., stopping one or more operations, generating an alarm, diverting the liquid for purification, supplying fresh liquid etc.).

[0102] Again, different liquids will exhibit different changes in their properties depending on the electrical and chemical properties of the liquid and how the properties change when the liquids are exposed to factors such as heat, chemical reactions, and so on. Accordingly, the voltage levels of the signals received by the signal processor 402 from the x and y wires may be different for different liquids under different operating conditions. The detection circuit 404 can store multiple lookup tables (e.g., received from the system controller 130 / 230) that store pre-calibrated values of signal levels for different liquids. The detection circuit 404 uses the values as thresholds for detecting changes in properties of different liquids. When the first and second leak detection sensors 300 are placed at points A and B in the tool, the liquid flowing from points A to B is known. The controller 400 may store many lookup tables for many liquids used in the tool. The systemcontroller 130 / 230 can program the controller 400 to select a lookup table for that liquid to detect a change in the property of the liquid.

[0103] Further, the sensitivity at which the leak detection sensor 300 detects a change in a property can be controlled by adjusting detection thresholds using lookup tables. For example, setting low thresholds (high sensitivity) can be useful in applications where none to minimal deviation in a property of the liquid is needed. For example, thresholds can be set high (low sensitivity) in applications where some change in a property of a liquid is tolerable (e.g., if the property of the liquid is restored downstream before resupplying the liquid). Depending on the location of the leak detection sensor 300 in the tool, the type of liquid, and the desired sensitivity for property detection, the controller 400 may store many lookup tables for many liquids used in the tool.

[0104] FIGS. 13-15 show nonlimiting examples of forming zones in the leak detection sensor 300. For example, in FIG. 13, the y1 and y2 wires are connected to each other (grouped), and the y3, y4, and y5 wires are connected to each other (grouped). The x wires are not connected to each other (grouped). The wires y1 , y2, and the x wires form a first zone z1 ; and the wires y3, y4, y5, and the x wires form a second zone z2.

[0105] When a drop of a leaking liquid falls anywhere in the first zone z1 , depending on where the drop falls in the first zone z1 , the electrical signal from the v wire is conducted by any of the y1 and y2 wires and by any of the x wires, and a leak is detected in the first zone z1 . When a drop of a leaking liquid falls anywhere in the second zone z2, depending on where the drop falls in the second zone z2, the electrical signal from the v wire is conducted by any of the y3, y4, and y5 wires and by any of the x wires, and a leak is detected in the second zone z2. The size of each zone can be adjusted by selecting the number of y wires grouped (connected) together in each zone.

[0106] In FIG. 14, the x1 and x2 wires are connected to each other (grouped), and the x3 and x4 wires are connected to each other (grouped). The y wires are not connected to each other (grouped). The wires x1 , x2, and the y wires form a first zone z1 ; and the wires x3, x4, and the y wires form a second zone z2.

[0107] When a drop of a leaking liquid falls anywhere in the first zone z1 , depending on where the drop falls in the first zone z1 , the electrical signal from the v wire is conducted by any of the x1 and x2 wires and by any of the y wires, and a leak is detected in the first zone z1 . When a drop of a leaking liquid falls anywhere in the second zone z2, depending on where the drop falls in the second zone z2, the electrical signal from the v wire isconducted by any of the x3 and x5 wires and by any of the y wires, and a leak is detected in the second zone z2. The size of each zone can be adjusted by selecting the number of x wires grouped (connected) together in each zone.

[0108] In FIG. 15, the x1 and x2 wires are connected to each other (grouped), the x3 and x4 wires are connected to each other (grouped), the y1 and y2 wires are connected to each other (grouped), and the y3, y4, and y5 wires are connected to each other (grouped). The wires x, x2, y1 , and y2 form a first zone z1 ; the wires x1 , x2, y3, y4, and y5 form a second zone z2; the wires x3, x4, y1 , and y2 form a third zone z3; and the wires x3, x3, y3, y4, and y5 form a fourth zone z4. The wires x1 , x2, y1 , and y2 form a first zone z1 ; the wires x3, x4, y1 , and y2 form a third zone z2.

[0109] When a drop of a leaking liquid falls anywhere in the first zone z1 , depending on where the drop falls in the first zone z1 , the electrical signal from the v wire is conducted by any of the x1 and x2 wires and by any of the y1 and y2 wires, and a leak is detected in the first zone z1 . When a drop of a leaking liquid falls anywhere in the second zone z2, depending on where the drop falls in the second zone z2, the electrical signal from the v wire is conducted by any of the x1 and x2 wires and by any of the y3, y4, and y5 wires, and a leak is detected in the second zone z2. When a drop of a leaking liquid falls anywhere in the third zone z3, depending on where the drop falls in the third zone z3, the electrical signal from the v wire is conducted by any of the x3 and x4 wires and by any of the y1 and y2 wires, and a leak is detected in the third zone z3. When a drop of a leaking liquid falls anywhere in the fourth zone z4, depending on where the drop falls in the fourth zone z4, the electrical signal from the v wire is conducted by any of the x3 and x4 wires and by any of the y3, y4, and y5 wires, and a leak is detected in the fourth zone z4. The size of each zone can be adjusted by selecting the number of x and y wires grouped (connected) together in each zone.

[0110] In FIGS. 13-15, the size of each zone determines the resolution at which the leak can be detected. The resolution is proportional to the size of the zone. A smaller zone detects the location of the leak with more accuracy than a larger zone. The size of each zone can be predetermined. Alternatively, while not shown, switches can be provided between the controller 400 and each of the x, y, and v lines. The controller 400 can activate and deactivate selected switches to change the zones. Since the zones are formed by selecting combinations of x and y wires, the zones can be generally called XY zones.

[0111] In FIGS. 12-15, while the detection circuit 404 is shown as part of the controller 400, the detections performed by the controller 400 can be performed by the system controller 130 / 230 instead. For example, the signal processor 402 can provide the data to the system controller 130 / 230, which can perform the operations of the detection circuit 404. Accordingly, the detections performed by jointly by the controller 400 and the system controller 130 / 230.

[0112] Further, the architecture of the controller 400 is scalable and can be extended to operate with multiple leak detection sensors 300. As mentioned above with reference to FIG. 4, the size of the leak detection sensor 300 itself is flexible. For example, the leak detection sensor 300 can be made with any number of the x and y wires and corresponding number of v wires. Further, the controller 400 can comprise one signal processor 402 and one detection circuit 404 that can operate with N leak detection sensors 300, where N > 1 . The controller 400 can comprise multiple sets of the signal processor 402 and the detection circuit 404 that can operate with N leak detection sensors 300. For example, N sets of the signal processor 402 and the detection circuit 404 can operate with N leak detection sensors 300, respectively. Alternatively, each set of the signal processor 402 and the detection circuit 404 can operate with different number of leak detection sensors 300.

[0113] The above configurations can be further extended by using multiple controllers 400 connected to each other with each controller 400 connected to multiple leak detection sensors 300. Any combination of the above configurations can be used. In some examples, depending on the size of the leak detection sensor 300 (e.g., if the number of the x, y, and v wires is very large), multiple controllers 400 can be connected together to operate with a single leak detection sensor 300 with one of the controllers 400 consolidating the processing performed by the other controllers 400 and detecting one leak or multiple leaks using the single leak detection sensor 300.

[0114] When the leak detection sensor 300 is zoned, in some examples, one set of the signal processor 402 and the detection circuit 404 (i.e., one controller 400) can operate all the zones. Alternatively, each set of the signal processor 402 and the detection circuit 404 can operate different zones. Depending on the size of the zones, one set of the signal processor 402 and the detection circuit 404 can operate some zones while another set of the signal processor 402 and the detection circuit 404 can operate other zones. Further, one set of the signal processor 402 and the detection circuit 404 can operatedifferent zones of different leak detection sensors 300. Furthermore, the sensitivity of leak detection in individual zones can be adjusted by providing different thresholds for different zones using lookup tables. Additionally, the zone sizes can be changed using switches as described above.

[0115] Any combinations of the above configurations (multiple controllers 400, multiple leak detection sensors 300, and multiple zones of varying sizes) can be used. In any of these configurations, some leak detection sensors 300 can perform leak detection, some leak detection sensors 300 can perform detecting changes in properties of liquids, and sensing liquid levels (described below).

[0116] Thus, the controller(s) 400 and the leak detection sensor(s) 300 can be configured in many different ways to provide the described functionalities. Furthermore, some of the functions of some of the leak detection sensors 300 can be performed by the controllers 400 while other functions of other leak detection sensors 300 can be performed by the system controller 130 / 230.EXAMPLES OF APPLICATIONS

[0117] FIGS. 16A-21 B show various examples of applications (use cases) in which the leak detection sensors 300 can be used. FIGS. 16A-16C show use of the leak detection sensor 300 in assemblies (e.g., power supplies) that have cutouts in the enclosures (e.g., for connecting bulkheads such as connectors to the assemblies). In such deployments, the leak detection sensor 300 is in the form of a sheet or a pad as shown. Only the second layer with the wire grid is shown, and the wire grid is shown such that the v wires are not explicitly shown separately. However, the wire grid is similar to that shown in FIG. 4.

[0118] Examples of cutouts are shown at 352, 354, 356, 358. The cutouts are areas in all three layers of the leak detection sensor 300 that align with the cutouts of the assembly. In FIG. 16A, the y wires are collected (individually or in groups if zones are used) on a first side of the leak detection sensor 300, and the x and v wires are collected (individually or in groups if zones are used) on a second side of the leak detection sensor 300. The collected wires are shown by thicker lines in FIGS. 16A-16C. The collected wires are connected to the connector 350, which can be used to connect the leak detection sensor 300 to the controller 400 for detecting the leak as described above. If the leak detection sensor 300 is zoned, the wires are collected per zone.

[0119] The cutouts in the leak detection sensor 300 create discontinuities in the mesh (the x, y, and v wires) of the leak detection sensor 300. If the cutouts are small, the discontinuities may not impair the ability of the leak detection sensor 300 to detect a leak. If the cutouts are large or if any failure to detect a leak due to the discontinuities in the mesh created by the cutouts is intolerable regardless of the size of the cutouts, to account for the discontinuities, wires from two or more sides of a cutout area in the leak detection sensor 300 can be utilized to sense leaks despite the discontinuities in the mesh as follows.

[0120] For example, in FIG. 16B, the y wires are additionally collected on a third side of the leak detection sensor 300. In another example, in FIG. 16C, the y wires are additionally collected on a third side of the leak detection sensor 300, and the x and v wires are additionally collected on a fourth side of the leak detection sensor 300. The additional wires can be collected (individually or in groups if zones are used) and connected to the connector 350. The configuration shown in FIG. 16C can detect a leak from any location in the leak detection sensor 300 regardless of the size, number, and location of the cutouts in the leak detection sensor 300.

[0121] Some assemblies in the tools may have cutouts on top and / or bottom. The leak detection sensor 300 with areas with the cutouts in the mesh that match the cutouts of an assembly can be placed on top of the assembly having cutouts. For an assembly having cutouts at the bottom of the assembly, the leak detection sensor 300 with areas with the cutouts that match the cutouts of the assembly can be placed on the bottom of the assembly, and the components of the assembly can be built on top of the leak detection sensor 300. Thus, the leak detection sensor 300 can be customized for individual assemblies in the tools.

[0122] FIG. 17 shows an example of an application where the leak detection sensor 300 is used as a cover for a fitting 450 used to supply a liquid. The leak detection sensor 300 is used as a cover to detect a leak in the fitting, to contain the leak, and to indicate the leak on the fitting itself. For example, the leak detection sensor 300 can be fabricated in the form of a cover that can be placed on top of (around) the fitting 450. The leak detection sensor 300 fully or partly surrounds the fitting 450. The leak detection sensor 300 is located external to the fitting 450.

[0123] The leak detection sensor 300 can act as a temporary seal since a small amount of leak from the fitting 450 can not only be contained within the cover formed by the leakdetection sensor 300 around the fitting 450 but can also be detected. Further, a leak indicator (e.g., an LED) 452 can be provided on the fitting 450 itself to facilitate service. The wires for connecting the leak indicator 452 to the controller 400 and the x, y, and v wires of the leak detection sensor 300 can be collected through a conduit and connected to the connector 350 that can be connected to the controller 400 for detecting the leak as described above. The controller 400 can activate the leak indicator 452 when a leak in the fitting 450 is detected by the leak detection sensor 300.

[0124] FIG. 18 shows an example of an application where the leak detection sensor 300 is in the form of a roll 460 or an adhesive tape that can be stuck to or wrapped around an assembly or a component of the tool to detect a leak in the assembly. For example, leak detection sensor 300 in the form of the roll 460 can be wrapped around a component (not shown) where a leak is likely to occur (e.g., under and / or around a conduit that can corrode over time and cause a leak). The roll 460 can comprise multiple leak detection sensors 300 and respective connectors 350, which can be connected to the controller to detect one or more leaks around the component.

[0125] FIG. 19 shows an example of an application where the leak detection sensor 300 in the form of the roll 460 and as an adhesive tape can be vertically stuck to or mounted to an inner wall of a liquid container 470 using an adhesive to detect a liquid level in the container. For example, the roll 460 comprising multiple leak detection sensors 300 arranged at predetermined distances can be installed vertically along the inner wall of the liquid container 470. As a level 472 of a liquid 474 in the liquid container 470 changes, the leak detection sensors 300 can detect the level 472 of the liquid 474 in the liquid container 470. This type of deployment of the leak detection sensor 300 can be useful in many applications in the tools. For example, the leak detection sensor 300 can be used to monitor liquid levels in capsules used to vaporize liquid precursors (e.g., in elements 1 14 shown in FIG. 1 A), in liquid containers that supply liquid coolants (e.g., in elements 120, 220 shown in FIG. 1 B), and so on.

[0126] FIGS. 20A-20C show an example of an application where the leak detection sensor 300 can be used to detect a change in a property of a liquid in a path of liquid flow. For example, a liquid is supplied to a processing chamber 500 via a first conduit 502 and recovered (e.g., returned to a liquid supply system, liquid recycling system, or a liquid filtering system) from the processing chamber 500 via a second conduit 504. A property of the liquid can change due to heat, a chemical reaction (e.g., a processperformed on a substrate in the processing chamber 500), and so on. If the liquid is simply reused (recirculated) during a next use of the liquid in the processing chamber 500, the changed property of the liquid may be undesirable.

[0127] To detect a change in a property of the liquid, the leak detection sensor 300 can be fabricated in the form of fittings (couplings) 510-1 , 510-2 (collectively called the fittings 510 and individually called the fitting 510) that can be installed in a path of liquid flow. FIG. 20A shows the deployment of the fittings 510 in the path of liquid flow. FIG. 20B shows the fitting 510 in detail. FIG. 20C shows a cross-section of the fitting 510 taken along line AA shown in FIG. 20B.

[0128] In each fitting 510, the x, y, and v wires of the respective leak detection sensor 300 can be collected through a conduit and connected to a respective connector 350-1 , 350-2 that can be connected to the controller 400 for detecting a change in a property of the liquid as described above with reference to FIGS. 12-15.

[0129] As shown in FIGS. 20B and 20C, the first fitting 510-1 comprises a first leak detection sensor 300-1 installed along an inner wall of the first fitting 510-1 (e.g., as a liner). The second fitting 510-2 comprises a second leak detection sensor 300-1 installed along an inner wall of the second fitting 510-2 (e.g., as a liner). As shown in FIG. 20A, the first fitting 510-1 can be installed in the path of liquid flow between the first conduit 502 and an input to the processing chamber 500. The second fitting 510-2 can be installed in the path of liquid flow between an output of the processing chamber 500 and the second conduit 504. The second fitting 510-2 is located downstream from the first second fitting 510-1 .

[0130] Using this type of deployment of the leak detection sensors 300-1 , 300-2 in the path of liquid flow, a change in a property such as concentration of the liquid can be detected across the flow path. For example, a change in concentration of the liquid may cause a change in electrical conductivity of the liquid. The change in electrical conductivity of the liquid is reflected in terms of changes in voltages of the second leak detection sensor 300-2 at the output of the processing chamber 500 relative to voltages of the first leak detection sensor 300-1 at the input of the processing chamber 500.

[0131] As described with reference to FIGS. 12-15, the controller 400 detects the change in electrical conductivity of the liquid based on the voltages received from the first and second leak detection sensors 300-1 , 300-2. The detected change can be communicated to the system controller 130 / 230 to perform relevant actions. For example,the actions may comprise purifying the liquid, stopping the flow of the liquid, and so on. Additionally, while not shown, a leak detector similar to the leak detector 452 shown in FIG. 17 can be installed on the fittings 510 to detect a leak at the fittings 510.

[0132] The fitting 510 can also be used to detect flow of a liquid through a conduit through which the liquid should not flow. The leak detection sensor 300 in the fitting 510 can sense presence or absence of liquid flow. When the controller 400 detects presence of a liquid in a conduit in which the liquid should not flow, the controller 400 can communicate the detection of the presence of the liquid in the conduit to the system controller 130 / 230, which can perform a relevant action. For example, the action may comprise stopping the flow of the liquid.

[0133] Further, the fitting 510 can also be used to detect flow of a liquid through a conduit through which the liquid should flow by sensing presence or absence of liquid flow. When the controller 400 detects absence of a liquid in a conduit in which the liquid should flow, the controller 400 can communicate the detection of the absence of the liquid in the conduit to the system controller 130 / 230, which can perform a relevant action. For example, the action may comprise starting the flow of the liquid. Additionally, while not shown, a leak detector similar to the leak detector 452 shown in FIG. 17 can be installed on the fittings 510 to detect a leak at the fittings 510.

[0134] The leak detection sensors 300 can also be used in processing chambers in which a wet treatment of substrates is performed using liquids. For example, an arrangement of the leak detection sensors 300 similar to that shown and described with reference to FIGS. 20A-20C above can be used in processing chambers in which a wet treatment of substrates is performed using liquids. For example, wet processing of a substrate can be performed using a liquid in the processing chamber 500 shown in FIG. 20A, and the leak detection and change of concentration of the liquid can be monitored using the leak detection sensors 300 arranged as shown in FIG. 20A.

[0135] For leak detection during wet processing of a substrate in a processing chamber (e.g., the processing chamber 500), in addition to the arrangement of the leak detection sensors 300 shown in FIG. 20A, one or more additional leak detection sensors 300 may be arranged under the processing chamber 500. One or more of the additional leak detection sensors 300 arranged under the processing chamber may also be zoned as described above.

[0136] FIGS. 21 A and 21 B show methods for leak detection and concentration monitoring performed during substrate processing using the leak detection sensors 300, respectively. FIG. 21 A shows a method 600 of detecting a leak of the liquid during substrate processing in a processing chamber. FIG. 21 B shows a method 650 of detecting a change in a property (e.g., concertation) of a liquid during substrate processing in a processing chamber. For example, the controller 400 shown in FIGS. 12- 15 can perform the methods 600 and 650.

[0137] In FIG. 21 A, at 602, the method 600 begins processing a substrate in a processing chamber and starts supply of a liquid. At 604, the method 600 selects a lookup table for detecting a leak as described above, and the leak detection sensors 300 begin monitoring a flow path of the liquid for any leak in the flow path of the liquid.

[0138] At 606, the method 600 determines if a leak is detected in the flow path of the liquid (e.g., the controller 400 determines if a voltage V from the v wires is detected on the x and y wires of the leak detection sensors 300; i.e., if a voltage V on the x and y wires is greater than zero). If the voltage V on the x and y wires is not greater than zero (i.e., if no leak is detected), at 608, the method 600 continues the processing of the substrate and supply of the liquid, and the method 600 returns to 604. If the voltage V on the x and y wires is greater than zero (i.e., if a leak is detected), the method 600 proceeds to 610.

[0139] At 610, the method 600 determines the location of the leak based on the X and Y coordinates of one of the leak detection sensors 300 and determines if the leak is greater than a predetermined threshold using the selected lookup table. If the leak is less than or equal to the predetermined threshold, at 612, the method 600 provides a warning about the detected leak, and executes a user defined command. For example, the user defined command can be a command selected by the user in the tool software to interrupt the substrate processing. Examples of the user defined command can include 1 ) shutoff or reduce the flow rate of the liquid supply and stop the tool after finishing the current processing; or 2) shutoff the liquid supply and turn off the tool without finishing the current substrate processing. At this point, depending on the user defined command, the method 600 can continue the substrate processing and return to 604, or the method 600 can end.

[0140] If the leak is greater than the predetermined threshold at 610, then at 614, the method 600 checks setpoints for the XY zones of the leak detection sensors 300 to identify the zone (location) where the leak is occurring, and determines the allowable leakquantity (e.g., an allowable range for the leak) from the selected lookup table. At 616, the method 600 determines if the leak is greater than the allowable range. If the leak is within (i.e., less than or equal to) the allowable range, at 618, the method 600 provides a warning about the detected leak and executes a user defined command as described above at 612 (i.e., the method 600 waits for the current processing of the substrate to complete before shutting down the liquid supply and halting the substrate processing). At this point, depending on the user defined command, the method 600 can continue substrate processing (e.g., to finish the current processing of the substrate) and return to 604, or the method 600 can end. If the leak is greater than the allowable range, at 620, the method 600 stops the substrate processing shuts off liquid supply, and the method 600 ends.

[0141] In FIG. 21 B, at 652, the method 650 begins processing a substrate in a processing chamber and starts supply of a liquid. At 654, the method 650 selects a lookup table for detecting a change in a property (e.g., concentration) of the liquid as described above, and the leak detection sensors 300 begin monitoring a flow path of the liquid for detecting the change.

[0142] At 656, the method 600 determines if a change in property of the liquid is detected based on the voltages of the leak detection sensors 300 as described above. If no change in property of the liquid is detected, at 658, the method 650 continues the processing of the substrate and supply of the liquid, and the method 650 returns to 654. If a change in property of the liquid is detected, the method 650 proceeds to 660.

[0143] At 660, the method 650 determines if the change in property of the liquid is greater than a predetermined threshold using the selected lookup table. If the change in property of the liquid is less than or equal to the predetermined threshold, at 662, the method 650 provides a warning about the detected change, and executes a user defined command. For example, the user defined command can be a command selected by the user in the tool software to interrupt the substrate processing. Examples of the user defined command can include 1 ) shutoff or reduce the flow rate of the liquid supply and stop the tool after finishing the current processing; or 2) shutoff the liquid supply and turn off the tool without finishing the current substrate processing. At this point, depending on the user defined command, the method 650 can continue the substrate processing and return to 654, or the method 650 can end. If the in property of the liquid is greater thanthe predetermined threshold at 660, then at 670, the method 650 stops the substrate processing shuts off liquid supply, and the method 650 ends.

[0144] Thus, the leak detection sensor 300 is a flexible, scalable, and multipurpose sensor. Since the leak detection sensors 300 can detect a liquid leak, a change in a property of the liquid in a flow path of the liquid, and a change in a level of a liquid in a liquid container, the leak detection sensor 300 can also be generally called a liquid detection sensor 300 or simply a liquid sensor 300.

[0145] The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims.

[0146] It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the examples is described above as having certain features, any one or more of those features described with respect to any one of the examples of the disclosure can be implemented in and / or combined with features of any of the other examples, even if that combination is not explicitly described. In other words, the described examples are not mutually exclusive, and permutations of one or more examples with one another remain within the scope of this disclosure.

[0147] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0148] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and / or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate.

[0149] The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0150] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, non-transitory memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software).

[0151] Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some examples, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0152] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of thewafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process.

[0153] In some examples, a remote computer (e.g., a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control.

[0154] Thus, as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0155] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0156] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboringtools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

Claims

CLAIMSWhat is claimed is:

1. A sensor comprising: a first layer of a first insulating material; a second layer comprising a grid of wires, the wires comprising insulated conductors arranged on the first layer, the grid of wires comprising: first wires arranged along a first axis; second wires arranged along a second axis intersecting the first axis; and third wires arranged along the first axis; wherein portions of the first, second, and third wires are partially uninsulated to partially expose respective conductors in regions where the first, second, and third wires intersect; and wherein partially insulated portions of the first, second, and third wires where the first, second, and third wires intersect lie between the partially exposed respective conductors; and a third layer comprising a mesh of a second insulating material arranged on the second layer.

2. The sensor of claim 1 wherein: the first wires and third wires are equal in number; and each of the first wires is adjacent to a corresponding one of the third wires.

3. The sensor of claim 1 wherein: each of the third wires is configured to receive a signal; and the signal from one of the third wires is coupled to one of the first wires and one of the second wires that intersect the one of the third wires in response to a liquid flowing through the mesh in the third layer into one of the regions of the second layer and contacting the one of the third wires in the one of the regions.

4. A system comprising the sensor of claim 3 and further comprising a controller connected to the grid of wires in the second layer, wherein the controller is configured to: supply the signal to the third wires; receive signals through one of the first wires and one of the second wires in response to the liquid contacting the one of the third wires in the one of the regions; anddetect presence of the liquid in the one of the regions based on the signals.

5. The sensor of claim 3 wherein the third layer comprises a layer of a salt that ionizes the liquid flowing through the mesh in the third layer into the second layer.

6. The sensor of claim 1 wherein: the grid of wires in the second layer is divided into a plurality of zones; and each zone of the plurality of zones comprises two or more wires of at least one of (i) the first wires and (ii) the second wires.

7. A system comprising the sensor of claim 6 and further comprising a controller connected to the grid of wires in the second layer, and wherein the controller is configured to: supply a signal to the third wires; receive signals through one of the first wires and one of the second wires in one of the plurality of zones in response to a liquid flowing through the mesh in the third layer and contacting one of the third wires in one of the plurality of zones; and detect presence of the liquid in the one of the plurality of zones based on the signals.

8. A system comprising a plurality of the sensor of claim 1 wherein: a first sensor of the plurality of the sensor is arranged at a first location of a path through which a liquid flows; and a second sensor of the plurality of the sensor is arranged at a second location of the path downstream from the first location; the system further comprising a controller connected to the grid of wires in the second layer of each of the first sensor and the second sensor, wherein the controller is configured to: supply a signal to the third wires of each of the first sensor and the second sensor; receive a first set of signals from the first wires and the second wires of the first sensor and a second set of signals from the second sensor in response the liquid following through the path, through the mesh in the third layer into the second layer of each of the first sensor and the second sensor, and contacting the third wires of each of the first sensor and the second sensor; anddetect a change in a property of the liquid based on the first set of signals and the second set of signals.

9. The system of claim 8 further comprising a first fitting and a second fitting, wherein the first sensor is arranged in the first fitting, and wherein the second sensor is arranged in the second fitting.

10. A system comprising: a fitting configured to flow a liquid therethrough; the sensor of claim 1 arranged around the fitting; and a controller connected to the grid of wires in the second layer of the sensor, wherein the controller is configured to: supply a signal to the third wires; receive signals through the one of the first wires and the one of the second wires in response to the liquid leaking from the fitting, flowing through the mesh in the third layer into one of the regions of the second layer, and contacting one of the third wires in the one of the regions of the second layer of the sensor; and detect presence of the liquid in the one of the regions of the second layer based on the signals.1 1 . The system of claim 10 wherein the fitting comprises an indicator arranged on the fitting, and wherein the controller is connected to the indicator and is configured to activate the indicator to indicate the liquid leaking from the fitting.

12. A system comprising a plurality of the sensor of claim 1 arranged in a roll that is wrapped around a component configured to flow a liquid therethrough, the system further comprising a controller configured to: supply a signal to the third wires of each of the plurality of the sensor; receive signals from one of the first wires and one of the second wires of one of the plurality of the sensor in response to the liquid leaking from the component, flowing through the mesh in the third layer into one of the regions of the second layer of the one of the plurality of the sensor, and contacting one of the third wires in the one of the regions of the one of the plurality of the sensor; and detect presence of the liquid in one of the regions of the one of the plurality of the sensor based on the signals.

13. A system comprising a plurality of the sensor of claim 1 arrange on an inner wall of a container configured to contain a liquid, the system further comprising a controller configured to: supply a signal to the third wires of each of the plurality of the sensor; receive signals from one of the first wires and one of the second wires of one of the plurality of the sensor in response to the liquid flowing through the mesh in the third layer into one of the regions of the second layer of the one of the plurality of the sensor, and contacting one of the third wires in the one of the regions of the one of the plurality of the sensor; detect presence of the liquid in one of the regions of the one of the plurality of the sensor based on the signals; and detect a level of the liquid in the container based on detecting presence of the liquid in the one of the regions of the second layer of the one of the plurality of the sensor.

14. A system comprising the sensor of claim 1 arranged on a surface of a component comprising a plurality cutout areas on the surface, wherein: the sensor is aligned with the surface of the component and comprises cutouts aligned with the cutout areas on the surface of the component; the grid of wires in the second layer of the sensor comprises discontinuities in the first, second, and third wires in the cutouts; the first wires and the third wires are collected from a first side of the sensor and are connected to a controller; and the second wires are collected from a second side of the sensor and are connected to the controller.

15. The system of claim 14 wherein the first wires and the third wires are collected from a third side of the sensor and are connected to the controller, and wherein the third side is opposite to the first side.

16. The system of claim 14 wherein the second wires are collected from a fourth side of the sensor and are connected to the controller, and wherein the fourth side is opposite to the second side.

17. The system of claim 14 further comprising the controller, wherein the controller is configured to:supply a signal to the third wires; receive signals through one of the first wires and one of the second wires in response to a liquid leaking on the surface of the component, flowing through the mesh in the third layer into one of the regions of the second layer, and contacting one of the third wires in the one of the regions of the second layer; and detect presence of the liquid in the one of the regions of the second layer based on the signals.

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