Sensor assemblies and methods of manufacturing thereof

Abstract

Some embodiments of this disclosure relate to a sensor assembly including a substrate, a housing, and a sensor die. In some embodiments, the substrate includes an outer region, an inner region, and an intermediate region between the outer and inner regions. In some embodiments, the substrate includes electrical contact pads located at least on the inner region. In some embodiments, the housing is coupled to the substrate at the intermediate region or the outer region to provide a hermetically sealed seal. In some embodiments, the sensor die is coupled to the substrate at the inner region via the electrical contact pads. The sensor die is aligned with the substrate via alignment features that align the sensor die relative to the substrate within at least one of a first plane or a second plane.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to a sensor for monitoring and controlling, for example, gas flow rate. Prior Art

[0002] Various manufacturing systems, such as those used in semiconductor applications, may include measurements of gas flow properties (e.g., flow rate, temperature, pressure, and the like). Sensors used to perform such measurements may be incompatible with the aggressive environments used in certain manufacturing systems (e.g., corrosive environments, environments with high-energy plasma, environments with vacuum, environments with high temperatures and / or frequent temperature cycling, and the like). Fabricating sensors and / or sensor packaging with specialized geometries that do not adversely affect process gas properties while also being compatible with certain aggressive environments can be challenging.

[0003] For example, in some manufacturing systems, process gases (e.g., gases used during semiconductor manufacturing processes) and / or cleaning gases (e.g., gases used to clean manufactured equipment and / or chambers used to manufacture electronic devices) may have precise delivery targets, including high mass flow rates and the ability to precisely control low flow rates. Conventional manufacturing systems typically use one or more mass flow controllers (MFCs) to measure and control the mass flow rates of process gases.

[0004] It would be advantageous to develop MFCs and / or other sensors that are compatible with aggressive manufacturing environments (e.g., resist corrosion and / or material contamination), remain vacuum-tight, are robust, have long operating lives, are reliable, and have geometries that minimize adverse effects on gas flow properties. Summary of the Invention

[0005] Certain embodiments of the present disclosure relate to a sensor assembly comprising a substrate, a housing, and a sensor die. In certain embodiments, the substrate comprises an outer region, an inner region, and an intermediate region positioned between the outer region and the inner region. In certain embodiments, the substrate further comprises electrical contact pads located at least on the inner region. In certain embodiments, the housing is coupled to the substrate at the intermediate region or the outer region to provide a hermetic seal. In certain embodiments, the sensor die is coupled to the substrate at the inner region via the electrical contact pads. The sensor die is aligned with the substrate via alignment features that align the sensor die relative to the substrate within at least one of a first plane or a second plane.

[0006] In another aspect of the present disclosure, a gas flow sensor configured to couple to a gas flow tube via a flange includes a dielectric substrate having an outer region, an inner region, and an intermediate region between the outer region and the inner region. The dielectric substrate includes electrical contact pads formed between layers of the dielectric substrate. The electrical contact pads extend from the outer region through the dielectric substrate to the inner region. A housing is coupled to the dielectric substrate at the intermediate region to form a hermetic seal. A sensor die is coupled to the dielectric substrate at the inner region via the electrical contact pads. The sensor die is aligned with the dielectric substrate via alignment features that align the sensor die relative to the dielectric substrate in at least a first plane or a second plane.

[0007] In another aspect of the present disclosure, a method includes the steps of providing a substrate having an outer region, an inner region, and an intermediate region positioned between the outer region and the inner region. The substrate further includes electrical contact pads located at least on the inner region. The method further includes the steps of aligning a sensor die with the substrate at the inner region via one or more alignment features, the one or more alignment features aligning the sensor die relative to the substrate in a first plane or a second plane. The method further includes the steps of coupling the sensor die to the substrate at the inner region. The method further includes the steps of coupling the substrate to a housing at the intermediate region or the outer region to provide a hermetic seal.

[0008] In another aspect of the present disclosure, a sensor assembly includes a substrate having an outer region, an inner region, and an intermediate region between the outer and inner regions. The substrate further includes electrical contact pads located at least on the inner region. The sensor assembly further includes a housing coupled to the substrate at the intermediate region or the outer region to provide a hermetic seal. The sensor assembly further includes a sensor die bonded to the substrate at the inner region. A metal adhesive bonds electrodes of the sensor die to the electrical contact pads. The metal adhesive includes platinum and / or one or more metals selected from tin, indium, copper, aluminum, and / or nickel.

[0009] In another aspect of the present disclosure, a method for manufacturing a sensor component includes the steps of providing a substrate having an outer region, an inner region, and an intermediate region between the outer region and the inner region. The substrate further includes a first electrical contact pad and a second electrical contact pad located at least on the inner region. The method further includes the steps of providing a sensor die having a first electrode and a second electrode. The first electrode includes a first metal wire extending from the sensor die, and the second electrode includes a second metal wire extending from the sensor die. The method further includes the steps of positioning the sensor die on the inner region of the substrate such that a portion of the first metal wire overlies the first electrical contact pad and the second metal wire overlies the second electrical contact pad. The method further includes the steps of bonding the first metal wire to the first electrical contact pad by a first welding operation. The method further includes the steps of bonding the second metal wire to the second electrical contact pad by a second welding operation. The method further includes the steps of coupling the substrate to a housing at the intermediate region or the outer region of the substrate to provide a hermetic seal.

[0010] In another aspect of the present disclosure, a method for manufacturing a sensor assembly is provided. The method includes the steps of providing a substrate having an outer region, an inner region, and an intermediate region between the outer region and the inner region. The substrate further includes electrical contact pads located at least on the inner region. The method further includes the steps of providing a sensor die having electrodes. The method further includes the steps of applying a multilayer reactive foil to at least one of: a) the electrical contact pads of the substrate or b) the electrodes of the sensor die. The method further includes the steps of positioning the sensor die on the inner region of the substrate such that the multilayer reactive foil is sandwiched between the electrical contact pads and the electrodes. The method further includes the steps of igniting the multilayer reactive foil to form a metallic bond between the electrical contact pads of the substrate and the electrodes of the sensor die. The method further includes the steps of coupling the substrate to a housing at the intermediate region or the outer region to provide a hermetic seal.

[0011] In another aspect of the present disclosure, a sensor assembly includes a housing having a first channel and a second channel. The first channel is configured to flow gas in a first direction, and the second channel is configured to flow gas in a second direction. The housing is configured to couple with a gas flow assembly. A substrate is disposed within the housing. The substrate has an outer region, an inner region, and a middle region. The inner region is located within the first channel, and the middle region is located between the outer region and the inner region. The substrate further includes electrical contact pads located at least on the inner region. A sensor die is coupled to the inner region of the substrate and is electrically connected to the electrical contact pads. The sensor die is disposed within the gas flow path of the first channel.

[0012] In another aspect of the present disclosure, a gas stick assembly includes a first end having an input configured to receive gas from a gas source. The gas stick assembly further includes a second end having an output configured to deliver the gas to a destination. The gas stick assembly further includes a valve between the first and second ends. The gas stick assembly further includes a sensor assembly between the first and second ends. The sensor assembly includes a housing having a first channel and a second channel. The first channel is configured to receive the gas from an upstream component of the gas stick assembly, and the second channel is configured to direct the gas to a downstream component of the gas stick assembly. The sensor assembly further includes a substrate within the housing. The substrate includes an outer region, an inner region, and a middle region. The inner region is located within the first channel and the middle region is located between the outer region and the inner region. The substrate further includes electrical contact pads located at least on the inner region. The sensor assembly further includes a sensor die coupled to the inner region of the substrate and electrically connected to the electrical contact pads. The sensor die is disposed in the air flow path of the first channel.

[0013] In another aspect of the present disclosure, a processing apparatus includes a processing chamber, a plurality of gas supplies, and a plurality of gas stick assemblies. Each of the gas stick assemblies is coupled between the processing chamber and a corresponding one of the plurality of gas supplies. The gas stick assembly includes a first end having an input configured to receive gas from the corresponding gas supply coupled to the gas stick assembly. The gas stick assembly further includes a second end having an output configured to deliver the gas to the processing chamber. The gas stick assembly further includes a valve between the first and second ends. The gas stick assembly further includes a sensor assembly between the first and second ends. The sensor assembly includes a housing having a first channel and a second channel. The first channel is configured to receive the gas from an upstream component of the gas stick assembly, and the second channel is configured to direct the gas to a downstream component of the gas stick assembly. The sensor assembly further includes a substrate within the housing. The substrate includes an outer region, an inner region, and an intermediate region. The inner region is located within the first channel and the intermediate region is located between the outer region and the inner region. The substrate further includes electrical contact pads located at least on the interior region. The sensor assembly further includes a sensor die coupled to the interior region of the substrate and electrically connected to the electrical contact pads. The sensor die is disposed within the airflow path of the first channel. Simple diagram description

[0014] The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals represent similar elements. It should be noted that different references to "a" or "one" embodiment in this disclosure do not necessarily refer to the same embodiment, and such references mean at least one.

[0015] FIG1 illustrates an exemplary system according to an embodiment of the present disclosure, including a process chamber, a gas source, and a flow control device. FIG1 also provides an exemplary illustration of various locations in which a sensor assembly according to an embodiment of the present disclosure may be incorporated into a process chamber and / or a manufacturing system.

[0016] FIG. 2 illustrates an exemplary flow control device according to an embodiment of the present disclosure.

[0017] FIG. 3 illustrates an exemplary sensor device that may be used in a sensor assembly according to an embodiment of the present disclosure.

[0018] FIG4A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0019] FIG4B illustrates an enlarged view of region A in FIG4A .

[0020] 4C illustrates a cross-sectional side view of an exemplary flow channel having the sensor assembly of FIG. 4A mounted thereon, according to an embodiment of the present disclosure.

[0021] 4D illustrates a cross-sectional view of a conformal coating formed on a surface of an exemplary sensor assembly, according to an embodiment of the present disclosure.

[0022] FIG. 5A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0023] FIG5B illustrates an enlarged view of region B in FIG5A.

[0024] 5C illustrates a perspective view of a multilayer ceramic substrate included in the sensor assembly of FIG. 5A , according to an embodiment of the present disclosure.

[0025] FIG. 5D illustrates a side view of the multilayer ceramic substrate of FIG. 5C .

[0026] FIG. 5E illustrates a top view of the multilayer ceramic substrate of FIG. 5C .

[0027] 5F illustrates a cross-sectional side view of an exemplary flow channel having the sensor assembly of FIG. 5A mounted thereon, according to an embodiment of the present disclosure.

[0028] FIG6A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0029] FIG6B illustrates an enlarged view of region C in FIG6A .

[0030] 6C illustrates a perspective view of a substrate included in the sensor assembly of FIG. 6A , according to an embodiment of the present disclosure.

[0031] 6D illustrates a cross-sectional side view of an exemplary flow channel having the sensor assembly of FIG. 6A , according to an embodiment of the present disclosure.

[0032] FIG. 7A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0033] 7B illustrates a perspective view of a multilayer ceramic substrate included in the sensor assembly of FIG. 7A , coupled with a sensor device at an interior region, according to an embodiment of the present disclosure.

[0034] FIG. 7C illustrates a side view of the multilayer ceramic substrate of FIG. 7B .

[0035] FIG. 7D illustrates a top view of the multilayer ceramic substrate of FIG. 7B .

[0036] FIG. 7E illustrates a front view of section AA in FIG. 7A .

[0037] FIG8A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0038] FIG8B illustrates a front view of cross section BB in FIG7E.

[0039] FIG. 9A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0040] 9B illustrates a perspective view of a multilayer ceramic substrate included in the sensor assembly of FIG. 9A , coupled with a sensor device at an interior region, according to an embodiment of the present disclosure.

[0041] FIG. 9C illustrates a front view of section CC in FIG. 9A .

[0042] FIG. 10A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0043] 10B illustrates a perspective view of a multilayer ceramic substrate included in the sensor assembly of FIG. 10A , according to an embodiment of the present disclosure.

[0044] FIG. 10C illustrates a front view of section DD in FIG. 10A .

[0045] 10D illustrates a cross-sectional side view of a sensor assembly according to an embodiment of the present disclosure.

[0046] FIG. 11A illustrates a flow chart of a method for adapting a sensor device for use in a flow control apparatus according to an embodiment of the present disclosure.

[0047] FIG. 11B illustrates a flow chart of a method for manufacturing a sensor assembly according to an embodiment of the present disclosure.

[0048] FIG. 11C illustrates a diagram of the method 1200 from FIG. 11B .

[0049] 12A-B illustrate cross-sectional side views of an exemplary flow channel with a sensor assembly mounted thereon, according to an embodiment of the present disclosure.

[0050] 13A illustrates a cross-sectional side view of an adapter / flange, a multilayer ceramic substrate, and a sensor device according to an embodiment of the present disclosure.

[0051] 13B illustrates an exploded cross-sectional side view of an adapter / flange, a multilayer ceramic substrate, and a sensor device according to an embodiment of the present disclosure.

[0052] 14A illustrates a side view of a ceramic substrate and sensor device according to an embodiment of the present disclosure.

[0053] 14B illustrates an exploded side view of a ceramic substrate and sensor device according to an embodiment of the present disclosure.

[0054] 14C illustrates a partial bottom view of a ceramic substrate and sensor device according to an embodiment of the present disclosure.

[0055] 14D illustrates a partially exploded bottom view of a ceramic substrate and sensor device according to an embodiment of the present disclosure.

[0056] 15A-G illustrate a system for bonding a sensor device to a ceramic substrate according to an embodiment of the present disclosure.

[0057] 16A-C illustrate a flow chart of a method for manufacturing a sensor assembly according to an embodiment of the present disclosure.

[0058] 16D-F illustrate a flow chart of a method for bonding a sensor device to a substrate according to an embodiment of the present disclosure.

[0059] FIG. 17A illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0060] FIG17B illustrates an elevation view of section EE in FIG17A.

[0061] FIG. 17C illustrates an exploded elevational view of section EE in FIG. 17A .

[0062] FIG17D illustrates a front view of section FF in FIG17A.

[0063] FIG17E illustrates a perspective view of a sensor assembly according to an embodiment of the present disclosure.

[0064] FIG17F illustrates a front view of section GG in FIG17F.

[0065] FIG17G illustrates a cross-sectional view of a sensor assembly according to an embodiment of the present disclosure.

[0066] 17H illustrates a schematic diagram of a sensor assembly coupled to an air stick assembly according to an embodiment of the present disclosure.

[0067] 17I illustrates a perspective view of a sensor assembly coupled to a gas stick assembly according to an embodiment of the present disclosure.

[0068] FIG. 18 is a block diagram illustrating a computer system for use in accordance with embodiments of the present disclosure. Implementation Method

[0069] Embodiments described herein relate to a sensor assembly (also referred to as a sensor package) adapted for use in a mass flow control device, a system incorporating the sensor assembly, a method of adapting the sensor assembly for such use, and a method of using the sensor assembly. In certain embodiments, the sensor assembly can also be adapted for uses other than as part of a mass flow control device. For example, the sensor assembly can be adapted for temperature control, pressure control, and similar applications. In some embodiments, the sensor assembly includes a sensor device (e.g., a MEMS device, a hot-wire anemometer (HWA) device, or any other suitable sensor) having a self-contained sensing element, which is positioned directly in the flow path of an airflow channel. In some embodiments, the sensor assembly also includes a substrate (e.g., a ceramic substrate) to which the sensor device is secured (e.g., via a metal adhesive or seal). In some embodiments, the sensor assembly also includes a housing to which the substrate is secured (e.g., via a metal seal). In some embodiments, the sensor device can be secured to the substrate via a metal adhesive (e.g., by welding, fusion bonding, the use of multiple layers of reactive foil, or brazing with a braze alloy), and the substrate can be secured to the housing via another metal adhesive or seal (e.g., by welding, fusion bonding, or brazing with a braze alloy). In some embodiments, an O-ring can be further disposed between the substrate and the housing. In some embodiments, the various components of the sensor assembly are assembled to provide a hermetic seal between the substrate (to which the sensor device is secured) and the housing (to which the substrate is secured at an outer region or at an intermediate region of the substrate). In some embodiments, the various components of the sensor assembly can be connected to establish continuous electrical conductivity from the self-contained sensing element, through the sensor assembly, to one or more external devices (e.g., processing equipment), allowing the properties measured by the sensing element to be transmitted to the processing equipment. The various components of the sensor assembly can also be connected to minimize the effects of flow turbulence on sensor measurements and / or to provide a hermetic seal to accommodate high vacuums and minimize outgassing or leakage. In some embodiments, the sensor assembly further includes a conformal coating (on a portion of the assembly or on the entire assembly) to protect various portions of the sensor assembly from corrosive gases.

[0070] In general, it is advantageous to precisely control the temperature and flow rate of process gases used in manufacturing to better control the process and enable precise processing constraints to be met. The low transient response rate of current flow sensors is not suitable for applications that benefit from precise control of gas dosage, such as delivering small amounts of gas and continuously delivering pulses of one or more gases.

[0071] Embodiments of the present disclosure advantageously overcome the limitations of current sensors by providing fast and accurate flow rate feedback using a sensor device (e.g., a MEMS device, a hot wire anemometer (HWA), or any other suitable sensor) located directly within the gas flow path. In addition to flow rate feedback, the sensor device can also advantageously be used to provide fast and accurate temperature measurements at any location in the gas supply pipeline, including at the source, near a valve, near the inlet of a process chamber (e.g., a delivery point), within the process chamber, or in the foreline. The temperature measurements can be monitored in real time by processing equipment, which can in turn transmit power output commands to heating units at various locations in the gas supply pipeline.

[0072] Certain embodiments advantageously adapt sensor devices for direct insertion into a gas flow path while protecting the sensor device from corrosive chemicals. For example, embodiments described herein relate to sensor assemblies and materials for sensor assemblies that can be exposed to corrosive chemicals, such as those used during semiconductor processing. The sensor assemblies described herein can be adapted to protect the sensor device from corrosive chemicals while still preserving the sensor device's electrical properties (e.g., establishing conductivity to the sensor), relative shape, and geometric configuration. In one embodiment, a sensing element (e.g., a nanowire portion) is positioned within the sensor device so that it is exposed to the flow path and can provide accurate measurements of gas flow. The sensor assembly can also be adapted to minimize turbulent flow effects on the sensor device's measurements, minimize corrosion, minimize deposits on the sensor die that could hinder sensor performance, minimize outgassing or leakage to the external environment, maintain vacuum, maintain thermal properties, maintain the sensitivity and / or measurement accuracy of the sensor device, and maintain a fast response time of the sensor device.

[0073] In some embodiments, the sensor die and / or the substrate to which the sensor die is bonded include one or more alignment features to facilitate alignment of the sensor die with the substrate in one or more planes. For example, a first alignment feature (e.g., alignment pins and / or holes) can be used to align the sensor die with the substrate in a first plane, perpendicular to the interface between the sensor die and the substrate. Additionally or alternatively, a second alignment feature (e.g., a solder joint with controlled thickness) can be used to align the sensor die with the substrate in a second plane, parallel to the interface between the sensor die and the substrate. The first alignment feature, the second alignment feature, and / or the third alignment feature (e.g., a recess in the substrate sized to receive at least a portion of the sensor die) can additionally or alternatively facilitate positioning the sensor die at a target location on the substrate, allowing the sensor die to be assembled. The one or more alignment features, then located in the center of the gas channel, can facilitate centering and / or placement of the sensor die at the target location, with the sensor die rotated and / or tilted relative to the substrate. By carefully controlling the placement, rotation, tilt, and / or orientation of the sensor die relative to the substrate (and therefore the airflow path in which the sensor assembly will be used), the sensor assembly configuration can be optimized. Slight variations in the rotation, tilt, and / or placement of the sensor die on the substrate can significantly affect measurements due to phenomena such as turbulence in the airflow path. By ensuring minimal tilt, rotation, etc., and / or that the sensor die is centered in the airflow path, turbulence effects can be minimized and sensor-to-sensor repeatability can be improved.

[0074] In some embodiments, the sensor die is bonded (e.g., brazed and / or soldered) to the substrate via a metal adhesive between the substrate's electrical contact pads and the sensor die's electrodes. The metal adhesive may include platinum, tin, indium, copper, aluminum, or nickel. For example, in embodiments where the sensor assembly will be used in a corrosive environment (e.g., one containing chlorine, bromine, etc.), the metal adhesive may include platinum, aluminum, or nickel. In benign environments (e.g., non-corrosive environments), tin, indium, or copper may be used for the metal adhesive. In some embodiments, the metal adhesive may include layers of aluminum and nickel. For example, a multilayer reactive foil comprising alternating layers of aluminum and nickel may be positioned between the sensor die's electrodes and the substrate's electrical contact pads. The foil may be ignited, causing the foil to react and bond to the electrodes and electrical contact pads. To enhance the metal adhesion, in some embodiments, a metal adhesion layer may be added to the sensor die's electrodes or to the substrate's electrical contact pads. The metal adhesion layer may include a layer of aluminum deposited on the electrodes or electrical contact pads. The metal adhesion layer may facilitate bonding of the foil to the electrodes and / or electrical contact pads. Alternatively, in some embodiments, the metal adhesive includes metal wires bonded to the electrodes of the sensor die and the electrical contact pads of the substrate. The metal wires may be platinum wires. The metal adhesive can reliably bond the sensor die to the substrate and establish reliable electrical connectivity between the sensor die and the substrate. Furthermore, in some embodiments, the metal adhesive can be substantially corrosion-resistant, allowing the sensor assembly to be used in corrosive environments (e.g., environments with corrosive gases). In corrosive environments, degradation of the electrical connection can significantly affect sensor measurements. By ensuring that the sensor die is bonded to the substrate with a reliable and / or corrosion-resistant adhesive, the sensor assembly can be effectively used in corrosive environments without being adversely affected by corrosion.

[0075] In some embodiments, the housing of the sensor assembly includes a first channel for flowing gas in a first direction and a second channel for flowing gas in a second direction. The first channel is configured to flow gas in a first direction, and the second channel is configured to flow gas in a second direction. A sensor die can be disposed in the first channel and coupled to the substrate. The housing can be configured to couple to the base of the gas stick assembly via one or more fasteners (e.g., threaded fasteners). The bottom surface of the housing can be configured to interface with the gas stick assembly. The housing can further be configured to couple with auxiliary components of the gas stick assembly (e.g., valves, filters, mass flow controllers, etc.). The top surface of the sensor assembly can be configured to interface with the auxiliary components. In some embodiments, the housing can be configured to couple between the base of the gas stick assembly and the auxiliary components. In some embodiments, the channels of the housing include openings on the top and bottom surfaces of the housing. The openings can have areas for receiving sealing components (e.g., O-rings, seals, etc.) to seal the interface between the housing and the base of the gas stick assembly and / or between the housing and the auxiliary components. In some embodiments, the sensor assembly includes multiple sensors (e.g., flow sensors, temperature sensors, pressure sensors, etc.). In some embodiments, the sensor housing includes a third channel that connects the first channel with the second channel within the housing. The housing can be configured to receive a plug to close the openings of the first channel and the second channel on the top surface of the housing, thereby directing airflow from the first channel to the second channel through the third channel. By configuring the housing to couple with the gas stick assembly, the sensor assembly can be included in the gas stick assembly. For example, a component of the gas stick assembly (such as a valve or filter) can be decoupled from the gas stick assembly, and the sensor assembly can be coupled to the gas stick assembly to replace the component. Thus, the sensor assembly can be modular in nature (e.g., capable of being easily coupled to the gas stick assembly in multiple locations). Furthermore, in some embodiments, the component can be coupled to the top of the sensor assembly. This sensor system allows for easy integration of the sensor assembly into the gas stick assembly and further facilitates rapid replacement of the sensor assembly on the gas stick assembly. Furthermore, the sensor assembly can be substantially resistant to the effects of corrosive gases encountered by the gas stick assembly, resulting in a longer lifespan for the sensor assembly than conventional systems or components.

[0076] FIG1 illustrates a system 100 according to an embodiment of the present disclosure, comprising a processing chamber 101, a gas source 160, and a flow control device 200. The processing chamber 101 can be used for processes that provide a corrosive plasma environment. For example, the processing chamber 101 can be a chamber used in a plasma etcher or plasma etching reactor, a plasma cleaner, or the like. In alternative embodiments, other processing chambers can be used that may or may not be exposed to a corrosive plasma environment. Some examples of chamber components include chemical vapor deposition (CVD) chambers, physical vapor deposition (PVD) chambers, ALD chambers, IAD chambers, etching chambers, and other types of processing chambers. In some embodiments, the processing chamber 101 can be any chamber used in electronic device manufacturing systems.

[0077] In one embodiment, processing chamber 101 includes a chamber body 102 and a showerhead 130, which enclose an interior volume 106. Showerhead 130 may include a showerhead base and a showerhead gas distribution plate (GDP), and may include a plurality of gas delivery holes 132 (also referred to herein as channels) throughout the GDP. Alternatively, showerhead 130 may be replaced by a lid and nozzle in some embodiments, or by a plurality of pie-shaped showerhead compartments and a plasma generation unit in other embodiments. Chamber body 102 may be fabricated from aluminum, stainless steel, or other suitable materials (e.g., titanium). Chamber body 102 generally includes sidewalls 108 and a bottom 110.

[0078] An outer liner 116 may be disposed adjacent the sidewall 108 to protect the chamber body 102. The outer liner 116 may be manufactured to include one or more holes. In one embodiment, the outer liner 116 is manufactured from alumina.

[0079] An exhaust port 126 may be defined in the chamber body 102 and may couple the interior volume 106 to a pumping system 128. The pumping system 128 may include one or more pumps and throttle valves that are used to evacuate and regulate the pressure of the interior volume 106 of the processing chamber 101.

[0080] A gas source 160 may be coupled to the processing chamber 101 to provide process gases and / or cleaning gases to the interior volume 106 via a showerhead 130 via a supply line 112. A flow control device 200 may be coupled to the gas source 160 and the processing chamber 101. The flow control device 200 may be used to measure and control the flow of gas from the gas source 160 to the interior volume 106. An exemplary flow control device 200 is described in more detail below with respect to FIG. 2. In some embodiments, one or more gas panels 160 may be coupled to the processing chamber 101 to provide gas to the interior volume 106. In such embodiments, one or more flow control systems 200 may be coupled to each gas source 160 and the processing chamber 101. In other embodiments, a single flow control device 200 may be coupled to one or more gas panels 160. In some embodiments, the flow control device 200 may include a flow ratio controller to control the flow of gas to the processing chamber 101 (e.g., via one or more supply lines 112) or to other processing chambers.

[0081] In some embodiments, a separate flow control device 200 is used for each gas supplied to the processing chamber. In some embodiments, each flow control device 200 is or includes a gas wand assembly, as described and illustrated below with respect to Figures 17H-I.

[0082] A showerhead 130 can be supported on a sidewall 108 of the chamber body 102. The showerhead 130 (or lid) can be opened to allow access to the interior volume 106 of the processing chamber 101 and can provide a seal for the processing chamber 101 when closed. A gas source 160 can be coupled to the processing chamber 101 to provide process gases and / or cleaning gases to the interior volume 106 via the showerhead 130 or lid and nozzle (e.g., via apertures in the showerhead or lid and nozzle).

[0083] In some embodiments, one or more sensor assemblies 170 can be disposed within the interior volume 106. For example, one or more sensor assemblies 170 can be located near (e.g., within 10 centimeters) the showerhead 130. As another example, one or more sensor devices can be located near (e.g., within 10 centimeters) the substrate 144, which can be used to monitor conditions near the reaction site.

[0084] In one embodiment, the substrate support assembly 148 includes a base 152 that supports an electrostatic chuck 150. The electrostatic chuck 150 further includes a thermally conductive base and an electrostatic puck bonded to the thermally conductive base by an adhesive, which in one embodiment may be a silicone adhesive. The thermally conductive base and / or the electrostatic puck of the electrostatic chuck 150 may include one or more optional embedded heating elements, embedded thermal insulators, and / or conduits to control the lateral temperature profile of the substrate support assembly 148. The electrostatic puck may further include a plurality of gas channels, such as grooves, mesas, and other surface features formed in the upper surface of the electrostatic puck. The gas channels may be fluidically coupled to a source of heat transfer (or backside) gas (e.g., helium) via holes drilled in the electrostatic puck. In operation, the backside gas may be provided to the gas channels at a controlled pressure to enhance heat transfer between the electrostatic puck and the supported substrate 144. The electrostatic chuck 150 may include at least one clamping electrode controlled by a clamping power supply.

[0085] FIG2 illustrates a flow control device 200 according to an embodiment of the present disclosure. Flow control device 200 can be configured to measure and control the mass flow rate of process gases and / or cleaning gases used in a manufacturing system and, therefore, can be considered an MFC. Flow control device 200 can be coupled to gas source 160 and chamber 101 via gas flow channel 240. The gas flow channel can correspond to supply conduit 112 of FIG1 . In some embodiments, flow control device 200 can be incorporated into a flow ratio controller or a pulsed mass flow system. In some embodiments, flow control device 200 can be part of a gas wand assembly, as described below with reference to FIG17H-I .

[0086] In some embodiments, the flow control device 200 may include at least a flow modulator 210, a sensor assembly 220, and a processing device 230. Gas from the gas source 160 flows through the flow modulator 210, through a flow path 242 defined by a gas flow channel 240, and toward the chamber 101. In other embodiments, the gas flow channel 240 may terminate somewhere outside of the chamber 101. For example, the gas flow channel 240 may deliver gas to an open environment (e.g., an exhaust system) or a closed environment (e.g., a building or vehicle ventilation system). In some embodiments, the gas flow channel 240 is a gas pipeline, a branch of a gas pipeline, or a separate component with an inlet and outlet mounted on the gas pipeline.

[0087] In some embodiments, flow modulator 210 is configured to restrict the flow of gas through flow path 242 and may include one or more flow modulating valves, each of which may be an actuable valve, such as an electroscrew valve or a piezoelectric valve. In some embodiments, the flow modulator includes other components in addition to valves, such as flow or temperature sensing components. In some embodiments, flow modulator 210 functions as an MFC, such as a heat-based MFC, a pressure-based MFC, or a decay rate-based MFC.

[0088] In some embodiments where the flow modulator 210 functions as a heat-based MFC, the flow modulator 210 includes a capillary bypass channel that branches off from the gas flow channel 240. Temperature sensors at the beginning and end of the capillary are used to calculate (e.g., by the processing device 230 or an onboard processing device) a temperature differential that is proportional to the gas flow rate.

[0089] In some embodiments, sensor assembly 220 is disposed downstream of flow modulator 210. Sensor assembly 220 can be a portion of flow modulator 210 (e.g., adjacent to a flow modulating valve of flow modulator 210), near flow modulator 210 (e.g., within 10 centimeters of flow modulator 210), near the inlet of chamber 101 or showerhead 130 (e.g., within 10 centimeters of flow modulator 210), or within chamber 101 (as described with respect to sensor assembly 170 in FIG. 1 , which can be the same as or similar to sensor assembly 220).

[0090] In some embodiments, the sensor assembly 220 includes a sensor device 222 that can be configured to generate one or more signals responsive to airflow conditions. For example, the sensor device 222 can be configured to generate one or more signals indicative of gas temperature or gas flow rate. An exemplary sensor assembly is described in more detail below with respect to Figures 4A through 10C. In some embodiments, the sensor assembly 220 is coupled to the airflow channel 240 such that the sensor device 222 is directly inserted into the flow path 242. The sensor assembly 220 is coupled to the airflow channel to form a seal to prevent gas leakage. In some embodiments, the sensor assembly 220 further includes a housing to which a substrate and the sensor device 222 (e.g., a MEMS device, a hot-wire anemometer (HWA)) are secured via a seal (e.g., a metal seal).

[0091] In some embodiments, the processing device 230 includes a central processing unit (CPU), a microcontroller, a programmable logic controller (PLC), a system-on-chip (SoC), a server computer, or other suitable type of computing device. The processing device 230 can be configured to execute programmed instructions related to the operation of the flow modulator 210. The processing device 230 receives feedback signals from the sensor device 222 and, optionally, the flow modulator 210, and calculates the temperature, flow rate, and / or other parameters of the gas flow. The processing device 230 further transmits control signals to the flow modulator 210 based on the received feedback signals. In some embodiments, the processing device 230 is configured for high-speed feedback processing and may include, for example, an EPM. In some embodiments, the processing device is configured to use the chamber 101 to execute a process recipe, or one or more steps of a process recipe, for a manufacturing process. For example, a recipe may specify that gas flow at a specific flow rate occur at a specific time, for a specific duration, and for specific gases. As another example, a recipe may specify pulses of one or more gases.

[0092] FIG3 illustrates a top view of an exemplary sensor device 300, which can be fabricated using fabrication techniques familiar to those skilled in the art. Sensor device 300 includes a support structure 302 having a substantially planar shape. Support structure 302 can be formed from an insulating material or a semiconductor, such as silicon, silicon with one or more oxide layers formed thereon, or any other suitable material.

[0093] In some embodiments, sensor device 300 includes an interface region (interface region 304) at one end of the sensor device and a sensor region (e.g., sensor region 306) at the other end of the sensor device. Interface region 304 can be suitable for coupling sensor device 300 to an external device (e.g., a ceramic substrate or other substrate), for example, via electrical contact pads on the substrate (as described in further detail with respect to Figures 4A to 10D and Figures 15A-G). Sensor region 306 can define a cavity 312 across which a free-standing sensing element 308 is suspended.

[0094] FIG3 also illustrates electrical contacts 314 (also referred to as electrodes) extending from one end of sensor device 300 (e.g., one end of interface region 304) to the other end of sensor device 300 (e.g., the other end on sensor region 306) and / or to sensing element 308. Sensing element 308 may be suspended between two electrical contacts 314. In one embodiment, sensing element 308 may be a nanowire. Electrical contacts 314 may be formed from one or more conductive metals. In certain embodiments, sensing element 308 may be made from the same conductive metal as electrical contacts 314. In one embodiment, sensing element 308 and / or electrical contacts 314 may be made from platinum. The electrodes may serve as electrical contacts to which one or more devices (e.g., processing device 230) may be operably coupled. In some embodiments, a portion of electrical contacts 314 may be affixed to a substrate (e.g., a ceramic substrate), as described in further detail with respect to the exemplary sensor assembly depicted in FIG4A through FIG10D. The electrical contacts 314 may serve as electrical contacts for interfacing with such external devices, thereby forming a closed electrical circuit during operation.

[0095] Certain embodiments described herein advantageously adapt sensor devices, such as the sensor device described with respect to FIG. 3 (or any other suitable sensor device), to be directly inserted into a gas flow channel (e.g., gas flow channel 240 in FIG. 2 ), while protecting the sensor device from the corrosive effects of aggressive gases (e.g., halogen-containing gases such as C₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃, SiF₄, etc., as well as other gases such as O₂ or N₂O) that may be utilized in a processing chamber (e.g., processing chamber 101). Further embodiments described herein advantageously adapt sensor devices, such as the sensor device described with respect to FIG. 3 (or any other suitable sensor device), to include a housing configured to be mounted on a gas stick assembly. The housing of such a sensor device may include one or more channels that provide a gas flow path across the sensing element of the sensor die. In embodiments, such sensor devices may be similarly protected from the corrosive effects of aggressive gases (e.g., halogen-containing gases such as C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, SiF4, etc., and other gases such as O2 or N2O) that may be utilized in a processing chamber (e.g., processing chamber 101).

[0096] In one example, embodiments described herein relate to sensor assemblies and materials for sensor assemblies that can be exposed to corrosive chemicals, such as those used during semiconductor processing. The sensor assemblies described herein can be adapted to protect the sensor device from the corrosive chemicals while still maintaining the sensor device's electrical properties, relative shape, and geometric configuration. The sensor assemblies can also be adapted to minimize the effects of flow disturbances on the sensor device's measurements (e.g., by carefully controlling the orientation and / or position of the sensor die relative to the substrate using one or more alignment features), minimize outgassing or leakage to the external environment, maintain vacuum, maintain thermal properties, maintain the sensitivity and / or measurement accuracy of the sensor device, and maintain the fast response of the sensor device. In certain embodiments, the sensor assemblies / packages described herein enable the use of fast-responding sensor devices (e.g., fast-responding MEMS-based hot-wire silicon flow sensors) in corrosive environments. In certain embodiments, the packaging described herein enables packaging and hermetically sealing sensor devices (e.g., fast-response MEMS-based hot-wire silicon flow sensors) and / or sensor assemblies without leaking to the external environment (e.g., leaks of vacuum and / or corrosive gases). In certain embodiments, the sensor assemblies / packages described herein enable positioning of the sensor device to maximize its effectiveness in avoiding turbulent flow effects. In certain embodiments, the sensor assemblies / packages described herein enable symmetrical positioning of the sensor device in the center of a flow path. In certain embodiments, the sensor assemblies / packages described herein enable optimization of coating thickness to reduce the impact on the sensitivity of the sensor device. Benefits of such assemblies / packages include enabling the use of fast-response sensor devices (e.g., fast-response MEMS-based hot-wire silicon flow sensors) in corrosive environments in a compact (in terms of size) and cost-effective manner. This can advantageously provide fast and accurate measurement of gas flow and temperature virtually anywhere in a tool, such as within a processing chamber.

[0097] FIG4A illustrates a perspective view of a sensor assembly 400 according to an embodiment of the present disclosure. In one or more embodiments, a sensor assembly (e.g., sensor assembly 400) includes a substrate (e.g., substrate 402). In one embodiment, substrate 402 may be a ceramic substrate. In certain embodiments, substrate (e.g., substrate 402) includes an outer region (e.g., outer region 402O) for coupling the substrate to a housing (e.g., housing 404), an inner region (e.g., inner region 402I) for coupling a sensor device (e.g., sensor device 300) to the substrate, and an intermediate region (e.g., intermediate region 402M) positioned between the outer region and the inner region. The term "external region," as used herein with respect to substrate 402 or any substrate described in any of the figures, refers to the region of the substrate that is adjacent to the external environment outside of gas flow channel 240. The term "inner region," as used herein with respect to substrate 402 or any substrate described in any of the figures, refers to the region of the substrate that is adjacent to the internal environment within gas flow channel 240. The term "intermediate region" as used herein with respect to substrate 402 or any substrate described in any other figure refers to the region of the substrate between the outer region and the inner region. In an embodiment, the intermediate region can be used to couple substrate 402 to housing 404.

[0098] In some embodiments, the substrate may be made of a dielectric material, such as sapphire. Sapphire may be a suitable substrate material because it has good corrosion resistance and can be machined into a suitable shape. In some embodiments, the substrate is a ceramic substrate. In some embodiments, a dielectric substrate (such as a sapphire substrate) can be machined into a suitable shape according to methods known to those skilled in the art. In some embodiments, the substrate 402 may have an elongated body with rounded edges (e.g., a cylindrical shape). In some embodiments, the substrate 402 has a cylindrical shape in its outer region 402O and at least a portion of its middle region 402M, with the cylindrical shape transitioning into a semi-cylindrical shape in its inner region 402I.

[0099] In certain embodiments, a substrate (e.g., substrate 402) may further include electrical contact pads (e.g., electrical contact pads 414) located at least on the interior region of the substrate. In one embodiment, substrate 402 includes electrical contact pads 414 on the semi-cylindrical planar surface of interior region 402I. Electrical contacts 314 on the interface region of sensor device 300 may be secured to electrical contact pads 414 on the interior region of the substrate (e.g., via a metal seal or adhesive). During operation, electrical contacts 314 on the sensor device, electrical contact pads 414 on the substrate, and one or more external devices (e.g., processing device 230) together form a closed circuit. Electrical contact pads (e.g., 414) on the substrate may be made of the same conductive material as electrical contact pads 314 on the sensor device. For example, in one embodiment, electrical contact pads 414 are made of platinum and may be metallized on the planar surface of interior region 402I of substrate 402 using procedures known to those skilled in the art.

[0100] In one embodiment, alignment features in the sensor device 300 and / or substrate 402 are used to align the sensor die to the substrate before and / or during bonding. Such alignment features are discussed below with reference to Figures 14A-15D, 16A, and 16D-16F. In one embodiment, the sensor device 300 is bonded to the substrate 402 using one or more metal bonding techniques, as discussed with reference to Figures 15E-G and 16B-16C.

[0101] In some embodiments, a substrate (e.g., substrate 402) can be coupled to a housing (e.g., housing 404) at its exterior region (e.g., 402O) to form a hermetic seal. In some embodiments, the housing can be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt-iron alloy), or another suitable material. In one embodiment, the housing can be made of stainless steel. In some embodiments, the substrate can be secured to the housing via a metal seal or adhesive (e.g., welding or brazing) to minimize gas leakage from the processing chamber environment to the external environment. In some embodiments, the substrate can be further secured to the housing via at least one additional leak-tight seal (e.g., a counterbore C-seal). In some embodiments, an O-ring can be further positioned between the substrate and the housing to further promote a hermetic seal between the substrate and the housing and minimize and / or eliminate vacuum leaks and / or leakage of corrosive gases from gas channel 240 through sensor assembly 400. In some embodiments, a cap can be placed between the base plate and the housing to engage (e.g., compress) the O-ring. In some embodiments, the cap can be secured to the housing by one or more fasteners (e.g., bolts, screws, etc.).

[0102] In the embodiment shown in FIG. 4A , substrate 402 is further machined to define a conductor pinhole extending along the entire length of the substrate, from the top of outer region 402O through middle region 402M to at least a portion of inner region 402I. In certain embodiments, substrate 402 further includes a conductor pin 416 within the conductor pinhole, wherein conductor pin 416 extends throughout inner region 402O and middle region 402M of substrate 402 and into at least a portion of inner region 402I of substrate 402. In certain embodiments, conductor pin 416 is secured to electrical contact pad 414 disposed on inner region 402I of substrate 402 via, for example, a metal seal. During operation, electrical contacts 314 on the sensor device, electrical contact pad 414 on the substrate, conductor pin 416, and one or more external devices (e.g., processing device 230) together form a closed circuit. Conductor pins (e.g., 416) extending across the entire length of the substrate can be made of the same conductive material as electrical contact pad 314 on the sensor device. For example, in one embodiment, conductor pin 416 is made of platinum.

[0103] FIG4B illustrates a magnified view of area A in FIG4A , with the connections between sensor device 300, substrate 402, electrical contact pads 414, and conductor pins 416 magnified. In the embodiment shown in FIG4B , sensor device 300 is coupled to electrical contact pads 414 on interior region 402I of substrate 402 via its electrical contacts 314. In one embodiment, the sensor device is coupled to electrical contact pads 414 via a first seal or adhesive 420A, which may be a metal seal or adhesive. As discussed in more detail below, the first metal seal or adhesive may be a platinum-to-platinum adhesive (e.g., resulting from the fusion bonding of two platinum contacts) or a metal adhesive comprising multiple metals (e.g., multiple different metal layers) created using a multilayer reactive foil (e.g., a nanolaminated foil) having alternating layers of two different metals. In other embodiments, the sensor device is coupled to the electrical contact pads 414 via welded joints (e.g., by electron beam welding or laser welding) or brazed joints (e.g., using a brazing alloy). In some embodiments, the sensor device is affixed to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is oriented perpendicularly relative to the direction of airflow (e.g., 242), as further described with respect to FIG. 4C . In some embodiments, the sensor device is affixed to the substrate such that the elongated support structure of the sensor device is oriented parallel to the direction of airflow, as further described with respect to at least the sensor assembly shown in FIG. 6D . Targeted orientation of the sensor device 300 relative to the substrate 402 can be achieved using one or more alignment features, as further described below.

[0104] In one embodiment, the outer region 402O of the substrate 402 is coupled / secured to the housing 404 via a second seal or adhesive 420B (which may be a metal seal or adhesive), for example, using a second braze alloy or welded joint. In certain embodiments, the outer region 402O of the substrate 402 may also be secured to the housing 404 via at least one additional leak-tight seal (e.g., a countersunk C-seal).

[0105] In the embodiment shown in FIG4B , conductor pin 416 is coupled / fixed to electrical contact pad 414 on inner region 402I of substrate 402. In one embodiment, conductor pin 416 is fixed to electrical contact pad 414 via third seal or adhesive 420C (which may be a metal seal or adhesive), for example, using a third braze alloy or welded joint, or a metal adhesive formed using a multilayer reactive foil (e.g., nanolaminated foil). In certain embodiments, conductor pin 416 may be further fixed to substrate 402 at intermediate region 402M, for example, using a fourth braze alloy or welded joint, via fourth seal or adhesive 420D (which may be a metal seal or adhesive), to form a hermetic seal to minimize or eliminate vacuum leakage and / or the passage of gas (e.g., corrosive gas) from gas channel 240 through conductor pin holes in substrate 402 through which conductor pin 416 passes.

[0106] Each of the first, second, third, and fourth seals, if present, can independently comprise an Al alloy, an Ag alloy, an Au alloy, a Ni alloy, a Si alloy, an Au-Ni alloy, a Ni-Pd alloy, a Ni-Y alloy, a Ni-Al alloy, a Ti alloy, or a combination thereof. In certain embodiments, the braze alloy, multilayer reactive foil, or weld material used for all seals is the same. In other embodiments, two or more different braze alloys or metal adhesive materials may be used for different seals. In one embodiment, at least one of seals 420A, 420B, 420C, or 420D comprises Sn-Ag-Ti as the braze alloy. It should be understood that the designations "first seal," "second seal," "third seal," and "fourth seal" should not be construed as restricting the order in which the various components in the sensor assembly described herein may be assembled, nor should they be construed as restricting the total number of seals in the sensor assembly. Rather, these designations are used merely for convenience in distinguishing one seal from another. Exemplary methods for making the various sensor assemblies described herein are described in more detail below with respect to Figures 11A-B and 16A-F.

[0107] In some embodiments, a sensor assembly (e.g., sensor assembly 400) further includes a non-conductive conformal coating on one or more surfaces or on at least a portion of the sensor assembly. The conformal coating can be a corrosion-resistant coating. In some embodiments, the coating covers part or all of the sensor device (e.g., 300). In some embodiments, the coating covers part or all of the sensor region 306 and / or the interface region 304 of the sensor device 300. In some embodiments, the coating covers part or all of the sensor region 306, including part or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 but not the sensing element 308. In some embodiments, the coating covers part or all of the substrate 402. In some embodiments, the coating covers the electrodes of the sensor device 300, the electrical contact pads of the substrate 402, and / or the metal bond between the sensor device 300 and / or the substrate 402. In some embodiments, the coating covers part or all of the outer region 402O, the middle region 402M, and / or the inner region 402I. In some embodiments, the coating covers part or all of the interior region 402I, including part or all of the electrical contact pads 414. In some embodiments, the coating covers part or all of the middle region 402M, including part or all of the conductor pins 416. In some embodiments, the coating covers part or all of the various seals (e.g., first seal 420A, second seal 420B, third seal 420C, and / or fourth seal 420D). In some embodiments, the sensor assembly can remain completely uncoated.

[0108] In some embodiments, the sensor assembly is first assembled so that electrical contacts are formed between all components of the sensor assembly (e.g., between the sensor device and the substrate, and between the substrate and the conductor pins), after which the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to the airflow when the sensor assembly is coupled to the airflow channel, as discussed below with respect to FIG. 4C .

[0109] In some embodiments, the coating is deposited using techniques such as ALD, IAD, low pressure plasma spray (LPPS), chemical vapor deposition (CVD), plasma spray chemical vapor deposition (PS-CVD), sputtering, combinations thereof, or other techniques suitable for forming conformal coatings, or modifications thereof. In some embodiments, the coating comprises a ceramic material that is resistant to corrosion from process gases or reactive species. For example, in some embodiments, the coating may include a plasma-resistant ceramic coating comprising a rare earth ceramic selected from the group consisting of Y2O3, YZrO, YxZryOz, YZrOF, Y3Al5O12, Y4Al2O9, YF3, YxOyFz, YOF, Er2O3, Er3Al5O12, ErF3, ExOyFz, ErOF, La2O3, Lu2O3, Sc2O3, ScF3, ScOF, Gd2O3, Sm2O3, Dy2O3, Y2O3-ZrO2 solid solution, ceramics comprising Y2Al4O9 and Y2O3-ZrO2 solid solution, or combinations thereof. In some embodiments, the coating comprises Al2O3. In one embodiment, the coating comprises Al2O3 deposited by atomic layer deposition (ALD). In some embodiments, the coating has a substantially uniform thickness, is conformal to the underlying surface being coated, is free of pores and cracks, can act as a diffusion barrier to metallic contaminants, and has a high purity (e.g., greater than approximately 99% purity, or greater than approximately 99.95% purity). In certain embodiments, ALD can advantageously be used to coat all dimensions of the sensor component. In some embodiments, the coating can resist cracking and / or delamination at various temperatures (e.g., up to 350°C).

[0110] In certain embodiments, the coating can have a uniform thickness that varies by less than about + / - 20%, varies by less than about + / - 10%, varies by less than about + / - 5%, or less when comparing the coating thickness at one location to the coating thickness at another location (or when comparing the coating thickness at one location to an average thickness of the coating, or when evaluating the standard deviation of the coating thickness among several locations).

[0111] In certain embodiments, the coating can conform to the underlying surface being coated, including underlying surface features and / or complex geometries and / or portions of the coating having a high aspect ratio. For example, the coating can conformally and uniformly coat portions having a high aspect ratio (e.g., length:width (L:W) or length:diameter (L:D) ranging from about 2:1 to about 500:1, about 5:1 to about 300:1, about 10:1 to about 150:1, about 15:1 to about 100:1, or about 20:1 to about 50:1).

[0112] In certain embodiments, the coating can be very dense and have very low porosity, for example, a porosity of less than about 1%, less than about 0.5%, less than about 0.1%, or no porosity (porosity of 0%). In certain embodiments, the coating can have a crack-free microstructure, be gas-tight, and have high dielectric breakdown resistance.

[0113] In certain embodiments, the coating can be deposited at low deposition temperatures (eg, deposition temperatures up to 350° C.), which can enable its use with a wide variety of materials.

[0114] Figure 4D illustrates a cross-sectional view of a conformal coating formed on the surface of an exemplary sensor component, according to an embodiment of the present disclosure. For simplicity, Figure 4D illustrates coating 420 on a portion of sensor component 400, which can be any portion of sensor component 400 described herein. Similarly, coating 420 can be deposited on any portion of any other sensor component described herein. In some embodiments, the coating comprises a plurality of layers 422A-422D deposited sequentially. In some embodiments, there may be more or fewer layers than shown, and the number of layers may range from 1 to 100, up to 500, or more. For example, multiple atomically thin or nearly atomically thin layers may be deposited, for example, using ALD. In some embodiments, the composition of each of layers 422A-422D may alternate. In some embodiments, the total thickness of the coating may range from 10 nm to 500 nm, any subrange therein, or any single value therein. In certain embodiments, the thickness of the coating is optimized to reduce the coating's effect on measurement sensitivity while also protecting the sensor assembly (and various components of the sensor assembly) from aggressive chemicals to which the sensor assembly may be exposed during processing.

[0115] FIG4C illustrates a cross-sectional side view of an exemplary flow channel (e.g., flow channel 240) coupled to the sensor assembly 400 of FIG4A according to an embodiment of the present disclosure. As shown in this figure, the sensor assembly 400 can be mounted on a manifold (e.g., a K1S T manifold (having a T-fitting 492)) via a suitable seal (e.g., a leak-proof seal (e.g., a C-seal)). The manifold can be coupled to the flow channel 240 (e.g., tubing) at opposite ends.

[0116] In certain embodiments, a housing (e.g., housing 404) may include a gas-facing surface 460 and an opposing surface 470 opposite the gas-facing surface. Housing 404 may have at least one slot (e.g., slot 480B) formed therethrough and configured to receive a substrate (e.g., substrate 402). Substrate 402 may be inserted into slot (e.g., slot 480B) such that an interior region 402I of the substrate extends from gas-facing surface 460, e.g., into the interior environment of a gas flow channel (e.g., gas flow channel 240). In certain embodiments, housing 404 may include at least one additional slot (e.g., 480A and 480C) configured to mount housing 404 on gas flow channel 240, e.g., via a suitable manifold and / or a suitable seal (e.g., C-seal 490) and / or a suitable fitting (e.g., T-fitting 492). Seal 490 may be a hermetic seal to prevent gas from leaking from gas flow channel 240 to the external environment. In some embodiments, seal 490 is a metal seal, such as formed by brazing or welding.

[0117] FIG5A illustrates a perspective view of a sensor assembly 500 according to an embodiment of the present disclosure. In one or more embodiments, a sensor assembly (e.g., sensor assembly 500) includes a substrate (e.g., substrate 502). In some embodiments, the substrate (e.g., substrate 502) includes an outer region (e.g., outer region 502O) that is optionally used to couple the substrate to a housing (e.g., housing 504), an inner region (e.g., inner region 502I) that is used to couple a sensor device (e.g., sensor device 300) to the substrate, and an intermediate region (e.g., intermediate region 502M) positioned between the outer and inner regions (and optionally used to couple the substrate to the housing). In some embodiments, the dielectric substrate can be a multilayer ceramic made of a plurality of ceramic layers. The multilayer ceramic substrate can be made of any dielectric ceramic material that can be formed into a suitable shape. In some embodiments, the dielectric multilayer ceramic substrate can be made of aluminum oxide (Al2O3) or aluminum nitride (AlN). In certain embodiments, the substrate can be made of AlN, Si, SiC, Al2O3, SiO2, and the like. Multilayer ceramic substrates can be advantageously used due to their high strength, good insulation, low thermal expansion coefficient, and good chemical stability. Multilayer ceramics can be manufactured by methods known to those skilled in the art, such as by processes including, but not limited to, one or more of the following: tape casting, tape cutting, framing, via punching, via filling, screen printing, lamination, dicing, co-firing, nickel plating, gold plating, or combinations thereof.

[0118] Figure 5C illustrates a perspective view of a multilayer ceramic substrate included in the sensor assembly of Figure 5A according to an embodiment of the present disclosure. Figure 5D illustrates a side view of the multilayer ceramic substrate of Figure 5C. Figure 5E illustrates a top view of the multilayer ceramic substrate of Figure 5C. In the embodiment shown in Figures 5C-5E, two ceramic layers are shown (e.g., a first layer 502A and a second layer 502B covering a portion of first layer 502A). In the depicted embodiment, ceramic layers 502A and 502B are in contact, achieving a hermetic seal between the layers. In the illustrated embodiment, electrical contact pads 514 are formed / built into the multilayer ceramic substrate 502 between the layers (e.g., electrical contact pads 514 are formed between first ceramic layer 502A and second ceramic layer 502B). Electrical contact pads 514 extend throughout the multilayer ceramic substrate, from its outer region 502O to its inner region 502I. One advantage of this substrate is that a hermetic seal is achieved between the ceramic layers of the multilayer ceramic and between the electrical contact pads formed between the layers. This hermetic seal reduces the number of fixed locations of the various components of the sensor assembly (optionally secured via metal seals (e.g., via brazing or welding)) and minimizes potential locations for vacuum and / or gas to leak from the internal environment in the gas channel 240.

[0119] Although substrate 502 is illustrated in Figures 5C-5E as having sharp corners (e.g., each layer having a rectangular shape), the present disclosure also contemplates multilayer ceramic substrates having rounded shapes with rounded edges, similar to the shape described for substrate 402 in sensor assembly 400. In certain embodiments, other substrate shapes may be used, and the present disclosure should not be construed as being limited to only the shapes shown in the figures.

[0120] In one embodiment, the electrical contacts 314 on the interface region of the sensor device 300 can be secured to electrical contact pads 514 on the inner region 502I of the substrate 502 (e.g., via a metal seal). During operation, the electrical contacts 314 on the sensor device, along with the electrical contact pads 514 on the substrate and one or more external devices (e.g., processing device 230), form a closed circuit. The electrical contact pads (e.g., 514) located between the layers of the multilayer ceramic substrate 502 can be made of the same conductive material as the electrical contact pads 314 on the sensor device. For example, in one embodiment, the electrical contact pads 514 are made of platinum.

[0121] In some embodiments, a substrate (e.g., substrate 502) can be coupled to a housing (e.g., housing 504) at its outer region (e.g., 502O) or at its intermediate region. In some embodiments, the housing can be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt-iron alloy), or another suitable material. In one embodiment, the housing can be made of stainless steel. In some embodiments, the substrate can be secured to the housing via a metal seal (e.g., welding or brazing) to minimize gas leakage from the processing chamber environment to the external environment. In some embodiments, the substrate can be further secured to the housing via at least one additional leak-proof seal (e.g., a counterbore C-seal).

[0122] In some embodiments, an O-ring 580 may be further disposed between the substrate 502 and the housing 504 to further promote an airtight seal between the substrate and the housing and minimize and / or eliminate vacuum leaks and / or leakage of corrosive gases from the gas passage 240 through the sensor assembly 500. In some embodiments, a cap may be placed between the substrate and the housing to engage (e.g., compress) the O-ring. The cap may be tightened to the housing using screws, bolts, or other fasteners to engage the O-ring.

[0123] FIG5B illustrates an enlarged view of area B in FIG5A , magnifying the connection between sensor device 300, substrate 502, and electrical contact pads 514. In the embodiment shown in FIG5B , sensor device 300 is coupled to electrical contact pads 514 on interior region 502I of substrate 502 via its electrical contacts 314. In one embodiment, the sensor device is coupled to electrical contact pads 514 via a first seal or adhesive 520A, which can be a metal seal or adhesive formed by welding, using multiple layers of reactive foil, fusing, or brazing (e.g., using a first braze alloy). In some embodiments, the sensor device is affixed to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is oriented perpendicularly relative to the direction of airflow (e.g., 242), as further described with respect to FIG5F . In some embodiments, the sensor device is affixed to the substrate such that the elongated support structure of the sensor device is oriented parallel to the direction of airflow, as further described with respect to at least the sensor assembly shown in FIG6D . In an embodiment, the orientation and placement of the sensor device 300 relative to the substrate 502 may be controlled using one or more alignment features, as described in more detail below.

[0124] In one embodiment, the outer region 502O of the substrate 502 is coupled / secured to the housing 504 via a second seal or adhesive 520B (which may be a metal seal or adhesive), for example, using a second braze alloy, welding, etc. In certain embodiments, the outer region 502O of the substrate 502 may also be secured to the housing 504 via at least one additional leak-proof seal (e.g., a counterbore C-seal). In certain embodiments, the substrate is secured to the housing via a hermetic seal to minimize and / or eliminate leakage of vacuum and / or gas from the gas passage 240.

[0125] Each of the first seal (520A) and the second seal (520B), if present, can independently comprise an Al alloy, an Ag alloy, an Au alloy, a Ni alloy, a Si alloy, an Au-Ni alloy, a Ni-Pd alloy, a Ni-Y alloy, an Al-Ni alloy, a Ti alloy, or a combination thereof. In certain embodiments, the alloy or metal used for all seals / adhesives is the same. In other embodiments, two or more different alloys / metals can be used for different seals / adhesives. In one embodiment, at least one of seals 520A or 520B comprises Ag-Cu as the brazing alloy. It should be understood that the designations "first seal," "second seal," etc. should not be construed as restricting the order in which the various components in the sensor assembly described herein may be joined, nor should they be construed as restricting the total number of seals in the sensor assembly. Rather, these designations are used merely for convenience in distinguishing one seal from another. Exemplary methods for manufacturing the various sensor assemblies described herein are described in more detail below with reference to Figures 11A-B and 16A-F.

[0126] In some embodiments, a sensor assembly (e.g., sensor assembly 500) further includes a non-conductive conformal coating on one or more surfaces or on at least a portion of the sensor assembly. The conformal coating can be a corrosion-resistant coating. In some embodiments, the coating covers part or all of the sensor device (e.g., 300). In some embodiments, the coating covers part or all of the sensor region 306 and / or the interface region 304 of the sensor device 300. In some embodiments, the coating covers part or all of the sensor region 306, including part or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 but not the sensing element 308. In some embodiments, the coating covers part or all of the substrate 502. In some embodiments, the coating covers part or all of the outer region 502O, the middle region 502M, and / or the inner region 502I. In some embodiments, the coating covers part or all of the inner region 502I, including part or all of the electrical contact pads 514. In some embodiments, the coating covers part or all of the middle region 502M. In some embodiments, the coating covers part or all of the various seals (e.g., first seal 520A and / or second seal 520B). In some embodiments, sensor assembly 500 is first assembled to form electrical contacts between all components of the sensor assembly (e.g., between the sensor device and the substrate), after which the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to the airflow when the sensor assembly is coupled to the airflow channel, as discussed below with respect to FIG. 5F . In some embodiments, the coating deposited on at least a portion of sensor assembly 500 can be similar to the coating described above as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, architecture, and the like). In certain embodiments, sensor assembly 500 remains completely uncoated.

[0127] FIG5F illustrates a cross-sectional side view of an exemplary flow channel (e.g., flow channel 240) coupled to the sensor assembly 500 of FIG5A according to an embodiment of the present disclosure. As shown in this figure, the sensor assembly 500 can be mounted on a manifold (e.g., a K1S T manifold (having a T-fitting 592)) via a suitable seal (e.g., a leak-proof seal (e.g., a C-seal)). The manifold can be coupled to the flow channel 240 (e.g., tubing) at opposite ends.

[0128] In certain embodiments, a housing (e.g., housing 504) may include a gas-facing surface 560 and an opposing surface 570 opposite the gas-facing surface. Housing 504 may have at least one slot (e.g., slot 580B) formed therethrough and configured to receive a substrate (e.g., substrate 502). Substrate 502 may be inserted into slot (e.g., slot 580B) such that an interior region 502I of the substrate extends from gas-facing surface 560, e.g., into the interior environment of a gas flow channel (e.g., gas flow channel 240). In certain embodiments, housing 504 may include at least one additional slot (e.g., 580A and 580C) configured to mount housing 504 on gas flow channel 240, e.g., via a suitable manifold and / or a suitable seal (e.g., C-seal 590) and / or a suitable fitting (e.g., T-fitting 592). Seal 590 may be a hermetic seal to prevent gas from leaking from gas flow channel 240 to the external environment. In some embodiments, seal 590 is a metal seal, such as formed by brazing or welding.

[0129] While sensor assembly 400 and sensor assembly 500 illustrate embodiments in which sensor device 300 is affixed to respective substrates such that the sensor device's support structure is oriented perpendicularly relative to the airflow direction (e.g., 242), in some embodiments, sensor device 300 may be affixed to a substrate such that the sensor device's support structure is oriented parallel to the airflow direction (e.g., 242). This exemplary embodiment will be described with respect to at least sensor assembly 600 in FIG. 6D.

[0130] FIG6A illustrates a perspective view of a sensor assembly 600 according to an embodiment of the present disclosure. In one or more embodiments, a sensor assembly (e.g., sensor assembly 600) includes a substrate (e.g., substrate 602). In certain embodiments, the substrate (e.g., substrate 602) includes an outer region (e.g., outer region 602O) that is optionally used to couple the substrate to a housing (e.g., housing 604), an inner region (e.g., inner region 602I) that is used to couple a sensor device (e.g., sensor device 300) to the substrate, and an intermediate region (e.g., intermediate region 602M) positioned between the outer region and the inner region and that is optionally used to connect the sensor device to the housing.

[0131] FIG6C illustrates a perspective view of a substrate (such as the substrate included in sensor assembly 600 of FIG6A ) according to an embodiment of the present disclosure. In the embodiment depicted in FIG6C , the substrate is made of a dielectric material, such as sapphire or ceramic. In the embodiment depicted in FIG6C , the substrate is machined sapphire with rounded edges. Substrate 602 is shown having a cylindrical shape in its central region 602M. In the illustrated embodiment, the cylindrical shape of region 602M transitions to a semi-cylindrical shape in inner region 602I. In the illustrated embodiment, the cylindrical shape of region 602M continues into a portion of outer region 602O until it reaches the top of outer region 602O. In the illustrated embodiment, the top of outer region 602O is shaped as a disk having a larger diameter than the cylindrical portions in regions 602O and 602M. The illustrated substrate further defines conductor pinholes 616H, which extend from the top of the outer region 602O of the substrate 602 to the bottom of the inner region 602I of the substrate 602 and are shaped to receive conductor pins 616, as described in greater detail below. In certain embodiments, a substrate (whether sapphire or multilayer ceramic) with rounded edges can provide stress relief, which can extend the operating life of the sensor assembly. The substrate 602 can be machined into the illustrated shape or any other suitable shape by means known to those skilled in the art.

[0132] In certain embodiments, the substrate (e.g., substrate 602) may further include electrical contact pads (e.g., electrical contact pads 614) located at least on the interior region of the substrate. Electrical contacts 314 on the interface region of the sensor device 300 may be secured to the electrical contact pads 614 on the interior region of the substrate (e.g., via a metal seal). During operation, the electrical contacts 314 on the sensor device, along with the electrical contact pads 614 on the substrate and one or more external devices (e.g., processing device 230), form a closed circuit. The electrical contact pads on the substrate (e.g., 614) may be made of the same conductive material as the electrical contact pads 314 on the sensor device. For example, in one embodiment, the electrical contact pads 614 are platinum and may be metallized on the substrate (e.g., machined sapphire substrate 602) using procedures known to those skilled in the art.

[0133] In some embodiments, a substrate (e.g., substrate 602) may be coupled to a housing (e.g., housing 604) at its outer region (e.g., 602O) and / or intermediate region 602M. In some embodiments, the housing may be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt-iron alloy), or another suitable material. In one embodiment, the housing may be made of stainless steel. In some embodiments, the substrate may be secured to the housing via a metal seal or adhesive (e.g., welding, fusion, or brazing) to minimize gas leakage from the processing chamber environment to the external environment.

[0134] In some embodiments, an O-ring may be further disposed between the substrate 602 and the housing 604 to further promote an airtight seal between the substrate and the housing and minimize and / or eliminate vacuum leaks and / or leakage of corrosive gases from the gas channel 240 through the sensor assembly 600. In some embodiments, a cap may be placed between the substrate and the housing to engage (e.g., compress) the O-ring. The cap may be secured by one or more fasteners (e.g., screws, bolts, etc.).

[0135] In the embodiment shown in FIG6A , substrate 602 further includes conductor pins 616 that extend across outer region 602O and middle region 602M of substrate 602, reaching the bottom of inner region 602I of substrate 602. Conductor pins 616 are received in substrate 602 through conductor pin holes 616H, which extend from the top of outer region 602O to the bottom of inner region 602I of substrate 602. In certain embodiments, conductor pins 616 are affixed to electrical contact pads 614, which are located at the bottom of inner region 602I of substrate 602. During operation, electrical contacts 314 on the sensor device, electrical contact pads 614 on the substrate, conductor pins 616, and one or more external devices (e.g., processing device 230) together form a closed circuit. Conductor pins (e.g., 616) extending across the substrate can be made of the same conductive material as electrical contact pads 314 on the sensor device. For example, in one embodiment, the conductor needle 616 is made of platinum.

[0136] Figure 6B illustrates a magnified view of area C in Figure 6A , with the connection between sensor device 300 and substrate 602 magnified. In the embodiment shown in Figure 6B , sensor device 300 is coupled to electrical contact pads 614 on interior region 602I of substrate 602 via its electrical contacts 314. In one embodiment, the sensor device is coupled to electrical contact pads 614 via a first seal or adhesive 620A (which may be a metal seal or adhesive), for example, using a metal weld, a first braze alloy, or a multilayer reactive foil (e.g., a nanolaminate foil). First seal 620A may include a welded seal (e.g., a welded joint). In certain embodiments, the sensor device is affixed to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is oriented parallel to the direction of airflow (e.g., 242), as further described with respect to Figure 6D . One of the primary differences between sensor assembly 600 and sensor assembly 400 is the orientation of sensor device 300. In certain embodiments, measurements obtained from a sensor assembly having a sensor device mounted in a parallel orientation can be less affected by gas flow recirculation and / or turbulence, and can improve conduction through the flow path. In certain embodiments, a sensor device (e.g., sensor device 300) mounted on a substrate in a parallel orientation (relative to the gas flow direction, e.g., 242) results in gas recirculation further away from the sensor tip, which minimizes the impact on the accuracy of sensor measurements. In certain embodiments, one or more alignment features can ensure proper alignment of sensor device 300 with substrate 602.

[0137] In one embodiment, the outer region 602O and / or the middle region 602M of the substrate 602 are coupled / secured to the housing 604 via a second seal or adhesive 620B (which may be a metal seal or adhesive), for example, using a second braze alloy, a welded joint, etc., and / or via a third seal or adhesive 620C (which may also be a metal seal or adhesive), for example, using a third braze alloy, a welded joint, etc. In certain embodiments, the outer region 602O of the substrate 602 may be further secured to the housing 604 via at least one additional seal, for example, a leak-proof seal (e.g., a counterbore C-shaped seal).

[0138] In the embodiment shown in FIG6B , the conductor pin 616 can be coupled / fixed to the electrical contact pad 614 and / or to the sensor device 300 at the bottom of the inner region 602I of the substrate 602 via a fourth seal or adhesive 620D (which can be a metal seal or adhesive), for example, using a fourth brazing alloy, welding, etc. In certain embodiments, the conductor pin 616 can also be fixed to the substrate 602 (e.g., at the bottom of the inner region 602I) via a fifth seal 620E (which can be a metal seal), for example, using a fifth brazing alloy. In certain embodiments, the conductor pin 616 can be fixed to the substrate 602 via a seal to minimize and / or eliminate vacuum leaks and / or leakage of corrosive gases from the gas channel 240 through the sensor assembly 600 (e.g., through the conductor pin hole 616H through which the conductor pin 616 passes).

[0139] Each of the first seal (620A), the second seal (620B), the third seal (620C), the fourth seal (620D), and the fifth seal (620E), if present, can independently comprise an Al alloy, an Ag alloy, an Au alloy, a Ni alloy, a Si alloy, an Au-Ni alloy, an Al-Ni alloy, a Ni-Pd alloy, a Ni-Y alloy, a Ti alloy, or a combination thereof. In certain embodiments, the braze alloy or weld used for all seals / adhesives is the same. In other embodiments, two or more different braze alloys or metal welds can be used for different seals / adhesives. In one embodiment, at least one of seals 620A, 620B, 620C, 620D, or 620E comprises Sn-Ag-Ti as the braze alloy. It should be understood that designations such as "first seal," "second seal," "third seal," "fourth seal," and "fifth seal" should not be construed as restricting the order in which the various components in the sensor assemblies described herein must be assembled, nor should they be construed as restricting the total number of seals in the sensor assemblies. Rather, these designations are used simply to conveniently distinguish one seal from another. Exemplary methods for manufacturing the various sensor assemblies described herein will be described in more detail below with reference to Figures 11A-B and 16A-F.

[0140] In some embodiments, a sensor assembly (e.g., sensor assembly 600) further includes a non-conductive conformal coating on one or more surfaces or on at least a portion of the sensor assembly. The conformal coating can be a corrosion-resistant coating. In some embodiments, the coating covers part or all of the sensor device (e.g., 300). In some embodiments, the coating covers part or all of the sensor region 306 and / or the interface region 304 of the sensor device 300. In some embodiments, the coating covers part or all of the sensor region 306, including part or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 but not the sensing element 308. In some embodiments, the coating covers part or all of the substrate 602. In some embodiments, the coating covers part or all of the outer region 602O, the middle region 602M, and / or the inner region 602I. In some embodiments, the coating covers part or all of the inner region 602I, including part or all of the electrical contact pads 614 and / or the conductor pins 616. In some embodiments, the coating covers part or all of the middle region 602M. In some embodiments, the coating covers part or all of the various seals (e.g., first seal 620A, second seal 620B, third seal 620C, fourth seal 620D, and / or fifth seal 620E). In some embodiments, the sensor assembly is first assembled to form electrical contacts between all components of the sensor assembly (e.g., between the sensor device, the conductor pins, and the substrate), and thereafter the assembled sensor assembly is coated such that the coating covers at least the portion of the sensor assembly that is exposed to the gas flow when the sensor assembly is coupled to the gas flow channel, as discussed below with respect to FIG. 6D . In some embodiments, if the coating covers the conductor pins 616 at a top side portion of the outer region 602O of the substrate 602 (e.g., the top side portion is the portion that is exposed to the external environment and extends from an opposing surface 670 of the housing that is opposite the gas-facing surface 660), a portion of the coating can be removed (e.g., etched) to expose at least a portion of the conductor pins 616. However, the exposed portion of the conductor pin 616 (in the external environment) can be coupled with one or more external devices (eg, processing device 230) to form a closed circuit during operation. In some embodiments, the sensor assembly 600 remains completely uncoated.

[0141] In some embodiments, the coating deposited on at least a portion of the sensor assembly 600 can be similar to the coating described above as suitable for coating at least a portion of the sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, architecture, and the like).

[0142] FIG. 6D illustrates a cross-sectional side view of an exemplary flow channel (eg, flow channel 240 ) coupled to the sensor assembly 600 of FIG. 6A , according to an embodiment of the present disclosure.

[0143] In certain embodiments, a housing (e.g., housing 604) may include a gas-facing surface 660 and an opposing surface 670 opposite the gas-facing surface. Housing 604 may have at least one slot (e.g., slot 680B) formed therethrough and configured to receive a substrate (e.g., substrate 602). Substrate 602 may be inserted into slot (e.g., slot 680B) such that an interior region 602I of the substrate extends from gas-facing surface 660, e.g., into the interior environment of a gas flow channel (e.g., gas flow channel 240). In certain embodiments, housing 604 may include at least one additional slot (e.g., 680A and 680C) configured to mount housing 604 to gas flow channel 240, e.g., via a suitable manifold (e.g., a K1H manifold) and / or via a suitable seal (e.g., C-seal 690) and / or via a suitable fitting. Seal 690 may be a hermetic seal to prevent gas leakage from gas flow channel 240. In some embodiments, seal 690 is a metal seal, such as formed by brazing or welding.

[0144] In some embodiments, the dimensions of sensor assembly 600 are larger than those of sensor assemblies 400 and 500 because substrate 602 is inserted into slot 680B with sensor device 300 affixed to substrate 602 in a parallel orientation relative to the direction of airflow 242 (rather than a perpendicular orientation as shown in sensor assemblies 400 and 500). In some embodiments, slot 680B can be shaped to accommodate insertion of substrate 602 with sensor device 300 coupled thereto in a parallel orientation without sensing element 308 contacting the perimeter of slot 680B.

[0145] FIG7A illustrates a perspective view of a sensor assembly 700 according to certain other embodiments of the present disclosure. In one or more embodiments, a sensor assembly (e.g., sensor assembly 700) includes a substrate (e.g., substrate 702). In certain embodiments, the substrate (e.g., substrate 702) includes an outer region (e.g., outer region 702O), an inner region (e.g., inner region 702I) for coupling a sensor device (e.g., sensor device 300) to the substrate, and an intermediate region (e.g., intermediate region 702M) positioned between the outer and inner regions. In certain embodiments, the substrate may be coupled to a housing (e.g., housing 704) at intermediate region 702M and / or outer region 702O. In certain embodiments, substrate 702 may be a multilayer ceramic fabricated from a plurality of ceramic layers, similar to the multilayer ceramic substrate 502 described with respect to sensor assembly 500.

[0146] FIG7B illustrates a perspective view of a multilayer ceramic substrate included in the sensor assembly of FIG7A , with sensor device 300 coupled to substrate 702 at inner region 702I, according to an embodiment of the present disclosure. FIG7C illustrates a side view of the multilayer ceramic substrate of FIG7B . FIG7D illustrates a top view of the multilayer ceramic substrate of FIG7B . In the embodiment shown in FIG7B-7D , two ceramic layers are shown (e.g., a first layer 702A and a second layer 702B covering a portion of first layer 702A at a middle region 702M). In the depicted embodiment, ceramic layers 702A and 702B are in contact, achieving a hermetic seal between the layers (similar to multilayer ceramic substrate 502 ). In the illustrated embodiment, electrical contact pads 714 are formed / built into the layers of multilayer ceramic substrate 702 (e.g., electrical contact pads 714 are formed between first ceramic layer 702A and second ceramic layer 702B). Electrical contact pads 714 extend throughout the multilayer ceramic substrate, from outer region 702O to inner region 702I. An advantage of such a substrate, such as substrate 502, is that a hermetic seal is achieved between the ceramic layers of the multilayer ceramic substrate and between the electrical contact pads formed between the layers. This hermetic seal reduces the number of locations where the various components of the sensor assembly are secured via metal seals (e.g., by brazing or welding).

[0147] Ceramic substrate 702 can be made of any suitable plasma-resistant ceramic, which can be formed into a suitable multilayer ceramic according to methods known to those skilled in the art, as explained above with respect to substrate 502. Similarly, ceramic substrate 702 can be made of materials similar to those described above with respect to substrate 502.

[0148] In one embodiment, the electrical contacts 314 on the interface region of the sensor device 300 can be secured to electrical contact pads 714 on the interior region of the substrate 702 (e.g., via a metal seal). During operation, the electrical contacts 314 on the sensor device, along with the electrical contact pads 714 on the substrate and one or more external devices (e.g., processing device 230), form a closed circuit. The electrical contact pads (e.g., 714) located between the layers of the multilayer ceramic substrate 702 can be made of the same conductive material as the electrical contact pads 314 on the sensor device. For example, in one embodiment, the electrical contact pads 714 are made of platinum.

[0149] In some embodiments, a substrate (e.g., substrate 702) may be coupled to a housing (e.g., housing 704) at its intermediate region (e.g., 702M). In some embodiments, the housing may be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt-iron alloy), or another suitable material. In one embodiment, the housing may be made of stainless steel. In some embodiments, the substrate may be secured to the housing via a metal seal or adhesive (e.g., brazing, laser welding, electron beam welding, etc.) to minimize gas leakage from the processing chamber environment to the external environment. In some embodiments, an O-ring may be disposed between substrate 702 and housing 704. In some embodiments, a cap configured to engage (e.g., compress) the O-ring may be disposed between substrate 702 and housing 704. The cap may be secured via one or more fasteners (e.g., one or more bolts, screws, etc.).

[0150] In an embodiment, sensor device 300 is coupled to electrical contact pads 714 on interior region 702I of substrate 702 via its electrical contacts 314. In one embodiment, the sensor device is coupled to electrical contact pads 714 via a first seal or adhesive 720A, which can be a metal seal or adhesive formed by welding, using multiple layers of reactive foil, welding, or brazing (e.g., using a first braze alloy). In some embodiments, first seal / adhesive 720A is formed by a welding operation (e.g., electron beam welding, laser beam welding, etc.). In certain embodiments, the sensor device is affixed to the substrate such that a support structure (e.g., 302) of the sensor device (e.g., 300) is oriented parallel to the direction of airflow (e.g., 242). In certain embodiments, the sensor device can be affixed to substrate 702 such that its support structure is oriented perpendicular to the direction of airflow (not shown). One or more alignment features can provide for accurate positioning and / or alignment of sensor device 300 relative to substrate 702.

[0151] In one embodiment, the middle region 702M of the substrate 702 is coupled / secured to the housing 704 via a second seal or adhesive 720B (which may be a metal seal or adhesive), for example, using a second braze alloy, metal welding, etc. In certain embodiments, the substrate 702 may be secured to the housing 704 via a hermetic seal to minimize leakage of vacuum and / or gas from the processing chamber environment and / or from the gas passage 240 to the external environment.

[0152] Each of the first seal / adhesive (720A) and the second seal / adhesive (720B), if present, can independently comprise an Al alloy, an Ag alloy, an Au alloy, a Ni alloy, a Si alloy, an Au-Ni alloy, a Ni-Pd alloy, a Ni-Y alloy, a Ni-Al alloy, a Ti alloy, or a combination thereof. In certain embodiments, the braze alloy or metal adhesive used for all seals is the same. In other embodiments, two or more different braze alloys or metals can be used for different seals / adhesives. In one embodiment, at least one of seals / adhesives 720A or 720B comprises Ag-Cu as the braze alloy. It should be understood that the designations "first seal," "second seal," etc., should not be construed as restricting the order in which the various components in the sensor assembly described herein may be joined, nor should they be construed as restricting the total number of seals in the sensor assembly. Rather, these designations are used merely for convenience in distinguishing one seal from another. Exemplary methods for making the various sensor assemblies described herein are described in more detail below with respect to Figures 11A-B and 16A-F.

[0153] In some embodiments, the sensor assembly (e.g., sensor assembly 700) further includes a non-conductive conformal coating on one or more surfaces or on at least a portion of the sensor assembly. The conformal coating can be a corrosion-resistant coating. In some embodiments, the coating covers part or all of the sensor device (e.g., 300). In some embodiments, the coating covers part or all of the sensor region 306 and / or the interface region 304 of the sensor device 300. In some embodiments, the coating covers part or all of the sensor region 306, including part or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 but not the sensing element 308. In some embodiments, the coating covers part or all of the substrate 702. In some embodiments, the coating covers part or all of the outer region 702O, the middle region 702M, and / or the inner region 702I. In some embodiments, the coating covers part or all of the inner region 702I, including part or all of the electrical contact pads 714. In some embodiments, the coating covers part or all of the middle region 702M. In some embodiments, the coating covers part or all of the various seals (e.g., first seal 720A and / or second seal 720B). In some embodiments, sensor assembly 700 is first assembled to form electrical contacts between all components of the sensor assembly (e.g., between the sensor device and the substrate), after which the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to the airflow when the sensor assembly is coupled to the airflow channel. In some embodiments, the coating deposited on at least a portion of sensor assembly 700 can be similar to the coating described above as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, architecture, and the like). In certain embodiments, sensor assembly 700 remains completely uncoated.

[0154] FIG7E illustrates a front view of section AA in FIG7A . In certain embodiments, a housing (e.g., housing 704 ) may include a gas-facing surface 760 and an opposing surface 770 opposite the gas-facing surface. Housing 704 may be shaped as an airflow channel, similar to airflow channel 240 . The diameter, width, and / or height of the housing (if the housing is shaped other than cylindrical / tubular) may be larger than the diameter of the airflow channel (e.g., 240 ). The larger diameter, width, and / or height of housing 704 may be configured to provide space for the sensor assembly without restricting airflow, thereby minimizing (or substantially eliminating) the effect on the airflow parameter being measured by the sensor device.

[0155] The housing 704 can have at least one slot (e.g., slot 780A) formed therethrough and configured to receive a substrate (e.g., substrate 702). The substrate 702 can be inserted into the slot (e.g., slot 780A) such that an interior region 702I of the substrate extends from the gas-facing surface 760, for example, into the interior environment of a gas flow channel (e.g., gas flow channel 240). In certain embodiments, the substrate 702 can be inserted into the slot 780A and secured to the housing 704 at a middle region 702M thereof in a cantilevered orientation such that the interior region 702I of the substrate extends from the gas-facing surface 760 into the interior environment of the gas flow channel, and the exterior region 702O of the substrate extends from the opposing surface 770 to the exterior region, as shown in the front elevation view of section AA in FIG. 7E.

[0156] In some embodiments, as illustrated in Figures 8A and 8B, housing 704 has a first slot 780A formed at a first end 765A (e.g., extending from gas-facing surface 760 to an opposing surface 770 opposite the gas-facing surface) and a second slot 780B formed at an opposing second end 765B (e.g., extending from gas-facing surface 760 to an opposing surface 770 opposite the gas-facing surface). This housing can accommodate a substrate 802, which can be similar to substrate 702. In some embodiments, substrate 802 is a multilayer ceramic substrate. An advantage of substrate 802 (like substrates 502 and 702) is that it achieves a hermetic seal between the ceramic layers of the multilayer ceramic substrate and between the electrical contact pads formed between the layers. This hermetic seal reduces the number of locations where various components of the sensor assembly are secured via metal seals (e.g., brazing or welding).

[0157] Ceramic substrate 802 can be made of any suitable plasma-resistant ceramic, which can be formed into a suitable multilayer ceramic according to methods known to those skilled in the art, as explained above with respect to substrate 502. Similarly, ceramic substrate 802 can be made of materials similar to those described above with respect to substrate 502.

[0158] Multilayer ceramic substrate 802 may include a first end 802A and a second end 802B opposite the first end. First end 802A of substrate 802 may include a first outer region 802O1, an inner region 802I, and a first intermediate region 802M1 positioned between first outer region 802O1 and inner region 802I. Second end 802B of substrate 802 may include a second outer region 802O2, an identical inner region 802I, and a second intermediate region 802M2 positioned between second outer region 802O2 and inner region 802I. Multilayer ceramic substrate 802 may include electrical contact pads 814 formed between the layers of multilayer ceramic substrate 802. Electrical contact pads 814 may extend throughout multilayer ceramic substrate 802 from first end 802A to second, opposite end 802B, as shown in the front view of cross-section BB in FIG. 8B .

[0159] The multilayer ceramic substrate 802 can be secured to the housing 704 at a first intermediate region 802M1 and a second intermediate region 802M2. In certain embodiments, the multilayer ceramic substrate can be inserted into the housing 704 via a first slot 780A that extends across the entire diameter (or width) of the housing 704 to a second slot 780B. The first end 802A of the multilayer ceramic substrate 802 can be positioned through the first slot 780A, and the second, opposing end 802B of the multilayer ceramic substrate 802 can be positioned through the second, opposing slot 780B. In this configuration, the first outer region 802O1 of the substrate 802 can extend from the opposing surface 770 of the housing 704 at the first end 765A to an outer region of the first end. Furthermore, in this configuration, the second outer region 802O2 of the substrate 802 can extend from the opposing surface 770 of the housing 704 at the second, opposing end 765B to an outer region of the second, opposing end. Furthermore, in this configuration, the interior region 802I of the substrate 802 can extend from the gas-facing surface 760 of the housing 704 at the first end 765A to the gas-facing surface 760 of the housing 704 at the second end 765B. In certain embodiments, the substrate 802 can be secured to the housing (e.g., by brazing) via a metal seal (e.g., brazing) (e.g., the first end 765A of the housing 704 is secured to the first intermediate region 802M1 of the substrate 802, and the second end 765B of the housing 704 is secured to the second intermediate region 802M2 of the substrate 802) to form a hermetic seal to minimize gas leakage from the processing chamber environment to the external environment. The seal between the housing 704 and the substrate 802 (or between the housing 704 and the substrate 702) can be a hermetic seal to prevent gas leakage and / or vacuum leakage from the gas flow channel 240. In some embodiments, the seal is a metal seal formed, for example, by brazing or welding using any of the brazing alloys described above. Various sealing configurations may be used as appropriate, as will be described and illustrated in greater detail with respect to Figures 9A-9C and 10A-10D.

[0160] In the embodiment shown in Figures 8A-8B, the sensor device 300 can be coupled to / secured to the substrate 802 at the inner region 802I. As described with respect to the previously described sensor assembly, the sensor device 300 can be secured to the substrate via a metal seal / adhesive between the electrical contacts 314 (on the sensor device 300) and the electrical contact pads 814 on the substrate 802. The metal seal / adhesive can be formed by brazing, welding, welding (e.g., laser welding or electron beam welding), using multilayer reactive foils, and the like. During operation, the electrical contacts 314 on the sensor device, along with the electrical contact pads 814 on the substrate and one or more external devices (e.g., processing device 230), form a closed electrical circuit. The electrical contact pads (e.g., 814) located between the layers of the multilayer ceramic substrate 802 can be made of the same conductive material as the electrical contact pads 314 on the sensor device. For example, in one embodiment, the electrical contact pads 814 are made of platinum.

[0161] The sensor device 300 can be mounted on the substrate 802 such that the support structure (e.g., 302) is oriented parallel to the direction of airflow (e.g., 242). In some embodiments, the sensor device can be mounted on the substrate 802 such that the support structure of the sensor device is oriented perpendicular to the direction of airflow (not shown).

[0162] In some embodiments, the sensor assembly shown in Figures 8A-8B further includes a non-conductive conformal coating on one or more surfaces or on at least a portion of the sensor assembly. The conformal coating can be a corrosion-resistant coating. In some embodiments, the coating covers part or all of the sensor device (e.g., 300). In some embodiments, the coating covers part or all of the sensor region 306 and / or the interface region 304 of the sensor device 300. In some embodiments, the coating covers part or all of the sensor region 306, including part or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 but not the sensing element 308. In some embodiments, the coating covers part or all of the substrate 802. In some embodiments, the coating covers part or all of the outer regions 802O1 and 802O2, the middle regions 802M1 and 802M2, and / or the inner region 802I. In some embodiments, the coating covers part or all of the inner region 802I, including part or all of the electrical contact pads 814. In some embodiments, the coating covers part or all of the various seals (e.g., first seal 820A between sensor device 300 and substrate 802, and / or second seal 820B between first intermediate region 802M1 of substrate 802 and first end 765A of housing 704, and / or third seal 820C between second intermediate region 802M2 of substrate 802 and second end 765B of housing 704). In some embodiments, sensor assembly 800 is first assembled to form electrical contacts between all components of the sensor assembly (e.g., between the sensor device and the substrate), after which the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to the airflow when the sensor assembly is coupled to the airflow channel. In some embodiments, the coating deposited on at least a portion of sensor assembly 800 can be similar to the coating described above as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, architecture, and the like). In certain embodiments, sensor assembly 800 remains completely uncoated.

[0163] It should be understood that designations such as "first seal," "second seal," and "third seal" should not be construed as restricting the order in which the various components in the sensor assemblies described herein must be assembled, nor should they be construed as restricting the total number of seals in the sensor assemblies. Rather, these designations are used simply to conveniently distinguish one seal from another. Exemplary methods for manufacturing the various sensor assemblies described herein will be described in more detail below with reference to Figures 11A-B and 16A-F.

[0164] As previously described, the substrate (e.g., 702 or 802) can be bonded to the housing (e.g., 704) at the intersection between the perimeter of the slot through the housing (e.g., the perimeter of slot 780A or slot 780B) and the perimeter of the substrate's central region (e.g., 702M, 802M1, or 802M2). However, in certain embodiments, the substrate's central region and the slot through the housing can also be shaped to allow for face-to-face bonding therebetween. Without intending to be limiting, it is believed that face-to-face bonding between the substrate (e.g., at the central region) and the housing can reduce stresses that may be generated during bonding. This exemplary face-to-face bonding is illustrated in Figures 9A-9C and 10A-10D.

[0165] FIG9A illustrates a perspective view of a sensor assembly 900 according to an embodiment of the present disclosure. As can be seen in FIG9A , sensor assembly 900 can include a housing 904, which can be similar to housing 704. Housing 904 can also include a gas-facing surface 960 and an opposing surface 970 opposite the gas-facing surface. Housing 904 can also include a slot 980A therethrough. In certain embodiments, housing 904 can include a tapered region at the perimeter of slot 980A, configured to create a flat surface at the perimeter of slot 980A, into which middle region 902M of substrate 902 can be bonded in a parallel orientation.

[0166] FIG9B illustrates a perspective view of a multilayer ceramic substrate 902 with a sensor device 300 coupled to an inner region. Like the other multilayer ceramic substrates described above, multilayer ceramic substrate 902 can be fabricated using methods known to those skilled in the art. Multilayer ceramic substrate 902 can have an inner region 902I, an outer region 902O, and an intermediate region 902M positioned between inner region 902I and outer region 902O, to which sensor device 300 can be affixed. In some embodiments, intermediate region 902M has a thickness and / or length greater than inner region 902I and / or outer region 902O. In some embodiments, intermediate region 902M has a first surface 902M1 and a second surface 902M2 opposite the first surface. When substrate 902 is affixed to housing 904, first surface 902M1 can be adjacent to opposing surface 970 of housing 904 and can be bonded in a face-to-face configuration.

[0167] In some embodiments, the shape of substrate 902 is formed using multiple ceramic layers using methods known to those skilled in the art. In some embodiments, a hermetic seal is achieved between the layers of the multilayer ceramic substrate. In some embodiments, electrical contact pads 914 are formed / built into the layers of multilayer ceramic substrate 902 (extending from outer region 902O to inner region 902I across the entire substrate 902), maintaining a hermetic seal even with the presence of electrical contact pads 914 between the layers.

[0168] Ceramic substrate 902 can be made of any suitable plasma-resistant ceramic, which can be formed into a suitable multilayer ceramic according to methods known to those skilled in the art, as explained above with respect to substrate 502. Similarly, ceramic substrate 902 can be made of materials similar to those described above with respect to substrate 502.

[0169] At least a portion or all of sensor assembly 900 can be coated with a protective coating, as previously described for other sensor assemblies. The coating deposited on at least a portion of sensor assembly 900 can be similar to the coating described above as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, architecture, corrosion resistance, and the like). In certain embodiments, sensor assembly 900 can remain completely uncoated.

[0170] FIG9C illustrates a front view of cross-section CC in FIG9A . As shown in FIG9C , sensor assembly 900 is similar to sensor assembly 700, except for the bonding between substrate 902 and housing 904. In sensor assembly 900, multilayer ceramic substrate 902, to which sensor device 300 is affixed (at inner region 902I) in a parallel orientation (relative to gas flow 242), is inserted into slot 980A (shown in FIG9C ) in a cantilevered configuration until first surface 902M1 of substrate middle region 902M contacts (face-to-face) the tapered perimeter of slot 980A (which is located on opposing surface 970 of housing 904). Substrate assembly 902 can then be affixed to housing 904, for example, via a metal seal (e.g., using a braze alloy) to form a hermetic seal to minimize leakage of gas and / or vacuum from gas channel 240 to the external environment.

[0171] Although not shown in the figures, sensor assembly 900 can also be modified so that the substrate extends from one end of the housing to the other end of the housing, similar to sensor assembly 800. With this modification, each end of the modified substrate can be secured to each corresponding end of the housing via face-to-face bonding similar to the bonding described with respect to sensor assembly 900.

[0172] FIG10A illustrates a perspective view of a sensor assembly 1000 according to an embodiment of the present disclosure. As can be seen in FIG10A , sensor assembly 1000 may include a housing 1004, which may be similar to housings 704 and 904. Housing 1004 may also have a gas-facing surface 1060 and an opposing surface 1070 opposite the gas-facing surface. Housing 1004 may also have a slot 1080A extending therethrough. In certain embodiments, housing 1004 may include a tapered region at the perimeter of slot 1080A, configured to create a flat surface at the perimeter of slot 1080A, to which a central region 1002M of substrate 1002 may be bonded in a parallel orientation. Alternatively, as shown in FIG10A , housing 1004 may include a region 1004M with square or rectangular flat sidewalls, to which the central region 1002 of substrate 1002 may be bonded in a parallel, face-to-face orientation. In certain embodiments, the housing 1004 may have tubular gas passages 1004C extending from two opposing sides of a region 1004M having square or rectangular flat sidewalls.

[0173] FIG10B illustrates a perspective view of a multilayer ceramic substrate 1002. Like the other multilayer ceramic substrates described above, multilayer ceramic substrate 1002 can be prepared using methods known to those skilled in the art. Multilayer ceramic substrate 1002 can have an inner region 1002I, an outer region 1002O, and a middle region 1002M positioned between inner region 1002I and outer region 1002O, to which sensor device 300 can be affixed. In some embodiments, middle region 1002M has a thickness and / or length greater than inner region 1002I and / or outer region 1002O. In some embodiments, middle region 1002M is shaped as a disk with rounded edges (e.g., oval or circular) and has a first surface 1002M1 and a second surface 1002M2 opposite the first surface. When substrate 1002 is affixed to housing 1004, first surface 1002M1 can be adjacent to opposing surface 1070 of housing 1004 and can be bonded in a face-to-face configuration.

[0174] In some embodiments, the shape of substrate 1002 is formed using multiple ceramic layers using methods known to those skilled in the art. In some embodiments, a hermetic seal is achieved between the layers of the multilayer ceramic substrate. In some embodiments, electrical contact pads 1014 are formed / built into the layers of multilayer ceramic substrate 1002 (extending from outer region 1002O to inner region 1002I across the entire substrate 1002), maintaining a hermetic seal even with the presence of electrical contact pads 1014 between the layers.

[0175] Ceramic substrate 1002 can be made of any suitable plasma-resistant ceramic, which can be formed into a suitable multilayer ceramic according to methods known to those skilled in the art, as explained above with respect to substrate 502. Similarly, ceramic substrate 1002 can be made of materials similar to those described above with respect to substrate 502.

[0176] In certain embodiments, the sensor assembly 1000 further includes an adapter / flange 1300. The adapter / flange 1300 can be formed as a flat plate having a ring defined by its central region, the ring being configured to surround a portion of the ceramic substrate 1002. The adapter / flange 1300 can have a first side 1300S1 (e.g., a side facing the housing) and a second side 1300S2 (e.g., a side facing the substrate) opposite the first side. The adapter / flange 1300 can have a rounded perimeter (e.g., an oval or circular perimeter, or a rectangular shape with curved edges). The adapter / flange 1300 can be bonded to the housing 1004 (e.g., an opposing surface 1070 of the housing 1004), for example, near the location of the slot 1080A (e.g., around the perimeter of the slot 1080A). For example, the flange / adapter 1300 can be welded (e.g., via electron beam welding) to the housing 1004 such that a first side 1300S1 of the adapter / flange 1300 is adjacent to the housing 1004 (e.g., an opposing surface 1070 of the housing 1004), as shown, for example, by numeral 1300D in FIG10D. In some embodiments, the flange / adapter 1300 can be brazed, welded, or soldered to the housing 1004. The adapter / flange 1300 can be secured to the housing 1004 in a parallel, face-to-face configuration.

[0177] The adapter / flange 1300 can be made of a material with a coefficient of thermal expansion between the coefficients of thermal expansion of the multilayer ceramic substrate 1002 and the coefficient of thermal expansion of the housing 1004. In certain embodiments, the housing 1004 has a first coefficient of thermal expansion (CTE1), the substrate 1002 has a second coefficient of thermal expansion (CTE2), and the adapter / flange 1300 has a third coefficient of thermal expansion (CTE3). In certain embodiments, the value of CTE3 is between CTE1 and CTE2. For example, the housing 1004 can be made of stainless steel with a CTE1, the dielectric multilayer ceramic substrate can be made of ceramic with a CTE2, and the adapter / flange 1300 can be made of Kovar (a nickel-cobalt-iron alloy) with a CTE3 between CTE1 and CTE2. In certain embodiments, the adapter / flange 1300 comprises stainless steel, a nickel alloy, a nickel-chromium-molybdenum alloy, a nickel-cobalt-iron alloy, or a combination thereof. In some embodiments, the substrate 1002 is secured to the adapter / flange 1300 such that the first surface 1002M1 may be adjacent to the second side 1300S2 of the adapter / flange 1300 and may be bonded thereto in a face-to-face configuration.

[0178] The substrate 1002 can be secured to the adapter / flange 1300 (if present) or to the housing 1004 (if the adapter / flange 1300 is absent) via a first metal seal 1300A (e.g., made of any of the metal alloys described above or any other suitable metal alloy, by welding or brazing). In one embodiment, the substrate 1002 can be secured to the adapter / flange 1300 using an Al alloy via brazing.

[0179] In certain embodiments, a back-up ring 1500 may be further disposed around a portion of the substrate 1002 between the flange 1300 and the housing 1004. The back-up ring may be formed as a flat plate having a ring defined in its central region, the ring being configured to surround a portion of the ceramic substrate 1002. The back-up ring may include a housing-facing side and a substrate-facing side opposite the housing-facing side. In certain embodiments, the substrate-facing side of the back-up ring may be secured to the housing-facing side of the flange / adapter 1300 via a second metal seal 1300B. The second metal seal 1300B may be a metal braze seal or weld formed from any of the metal alloys described above or any other suitable metal alloy. In certain embodiments, the ceramic back-up ring 1500 is configured to reduce stress at a joint, such as the joint between the flange / adapter 1300 and the housing 1004. The back-up ring 1500 may be configured to reduce thermal stress at the joint during its formation. The support ring 1500 may be secured to the flange / adapter 1300 and / or the housing 1004 via a parallel, face-to-face configuration.

[0180] Support ring 1500 can be made of a material having a coefficient of thermal expansion between the coefficient of thermal expansion of multilayer ceramic substrate 1002 and the coefficient of thermal expansion of housing 1004. In some embodiments, support ring 1500 is made of a ceramic material. In some embodiments, support ring 1500 can be made of the same material as substrate 1002 and / or housing 1004.

[0181] In some embodiments, after the support ring 1500 and the adapter / flange 1300 are secured to the substrate 1002, a sensor device (e.g., the sensor device 300) can be secured to the interior area of ​​the substrate 1002 via the third seal 1300C. Thereafter, the substrate 1002 with the support ring 1500, the adapter / flange 1300, and the sensor device 300 can be inserted into the housing 1004, and the adapter / flange 1300 can be secured (e.g., via electron beam welding) to the housing 1004 to form a hermetic seal to minimize vacuum and / or gas leakage from the gas channel 240 to the external environment.

[0182] Each of the first seal 1300A, the second seal 1300B, the third seal 1300C, and the optional fourth seal 1300D (if not welded), if present, can independently comprise an Al alloy, an Ag alloy, an Au alloy, a Ni alloy, a Si alloy, an Au-Ni alloy, a Ni-Pd alloy, a Ni-Y alloy, a Ti alloy, or a combination thereof. In some embodiments, the brazing alloy used for all seals is the same. In other embodiments, two or more different brazing alloys may be used for different seals. It should be understood that the designations "first seal," "second seal," "third seal," and "fourth seal" should not be construed as restricting the order in which the various components in the sensor assembly described herein must be assembled, nor should they be construed as restricting the total number of seals in the sensor assembly. Rather, these designations are used merely for convenience in distinguishing one seal from another. Exemplary methods for manufacturing the various sensor assemblies described herein are described in more detail below with reference to Figures 11A-B and 16A-F.

[0183] At least a portion or all of sensor assembly 1000 can be coated with a protective coating, as previously described for other sensor assemblies. The coating deposited on at least a portion of sensor assembly 1000 can be similar to the coating described above as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, architecture, corrosion resistance, and the like). In some embodiments, sensor assembly 1000 can be entirely uncoated.

[0184] FIG10C illustrates a front view of cross-section CC of FIG10A. As shown in FIG10C, sensor assembly 1000 is similar to sensor assemblies 700 and 900, except for the bonding between substrate 1002 and housing 1004. In sensor assembly 1000, multilayer ceramic substrate 1002, with sensor device 300 affixed thereto (at interior region 1002I) in a parallel orientation (relative to airflow 242), is inserted into slot 1080A (shown in FIG10F) in a cantilevered configuration until a first surface 1002M1 of a middle region 1002M of the substrate contacts (face-to-face with) either the tapered perimeter (not shown) of slot 1080A or the second side 1300S2 of the adapter / flange 1300 (which may be located on the opposing surface 1070 of housing 1004). The substrate assembly 1002 may then be secured to the adapter / flange 1300, for example, via a metal seal (eg, with a braze alloy or a welded joint).

[0185] Although not shown in the figures, sensor assembly 1000 can also be modified so that the substrate extends from one end of the housing to the other end of the housing, similar to sensor assembly 800. With this modification, each end of the modified substrate can be secured to each corresponding end of the housing via an intermediate adapter / flange via face-to-face bonding similar to the bonding described for sensor assembly 1000.

[0186] FIG11A illustrates a method 1100 for adapting a sensor device for use in a flow control device according to an embodiment of the present disclosure. At block 1110, a substrate is provided. The substrate may have an outer region, an inner region, and an intermediate region positioned between the outer region and the inner region, and may further have electrical contact pads positioned at least on the inner region. Exemplary substrates of this type are shown in the sensor assemblies described above, such as substrates 402, 502, 602, 702, 802, 902, and 1002. In some embodiments, prior to providing the substrate, the substrate may be machined into the shapes described above or any other suitable shape. In some embodiments, the electrical contact pads may be metallized into the inner region of the substrate. In some embodiments, prior to providing the substrate, the substrate may be formed as a multilayer ceramic substrate having any of the shapes described above (or any other suitable shape), with the electrical contact pads formed between layers of the multilayer ceramic substrate, such that the electrical contact pads extend across the entire multilayer ceramic substrate from the outer region to the inner region.

[0187] At block 1120, a sensor device (e.g., sensor device 300 depicted in FIG. 3 or any other suitable sensor device) may be coupled to the substrate at an interior region of the substrate. The sensor device may be coupled to the substrate according to the embodiments described below with respect to FIG. 15A-G and 16A-F. In some embodiments, the sensor device includes a support structure comprising an interface region (e.g., interface region 304) at one end of the sensor device and a sensor region (e.g., sensor region 306) at the other end of the sensor device. The sensor region may include a free-standing sensing element (e.g., sensing element 308) suspended from the sensor region. The sensor device may further include electrical contacts (e.g., electrical contacts 314) extending from the sensing element to the top of the interface region along the entire length of the elongated support structure. The sensor device may be secured / coupled to the substrate such that the electrical contacts on the sensor device contact electrical contact pads on the substrate to establish a continuous and closed electrical circuit for transmitting signals from the sensor device to a processing device (e.g., processing device 230).

[0188] In some embodiments, the sensor device can be secured to the substrate by forming a first seal / adhesive between electrical contact pads (e.g., 414, 514, 614, 714, 814, 914, or 1014) on the substrate and electrical contacts on the sensor device (e.g., 314). Some embodiments of securing the sensor device to the substrate by forming a first seal / adhesive are described with reference to Figures 15A-G and 16B-F. In some embodiments, the sensor device in any of the sensor assemblies contemplated herein can be secured to the substrate via brazing, welding, the use of multi-layer reactive foils, or welding (or any other chemical means of attaching the sensor device to the substrate). In some embodiments, the sensor device in any of the sensor assemblies contemplated herein can be secured to the substrate via a heat source (e.g., laser welding, electron beam welding, etc.). In some embodiments, the sensor device and / or substrate are substantially transparent to the wavelength of radiation used by the electron beam welder or laser welder. Thus, radiation (e.g., light) from the welder can pass through the sensor device or substrate to heat the interface between the sensor device and the substrate to form a weld. The sensor device can be mounted on the substrate in a vertical orientation (e.g., in sensor assemblies 400 and 500) or in a parallel orientation (e.g., in sensor assemblies 600, 700, 800, 900, and 1000). In embodiments, one or more alignment features can be used to ensure the correct orientation of the sensor device relative to the substrate.

[0189] In certain embodiments where the substrate includes conductor pins extending over the entire outer region and the middle region of the substrate into at least a portion of the inner region of the substrate (e.g., substrates 402 and 602), the method may further include the step of securing the conductor pins to electrical contact pads at the inner region of the substrate (e.g., as described with sensor assemblies 400 and 600), for example, with a third metal seal (e.g., via brazing).

[0190] At block 1130, the substrate is inserted into a slot in a housing (e.g., any of housings 404, 504, 604, 704, 904, or 1004 described above) such that the interior region of the substrate extends from the gas-facing surface of the housing. In certain embodiments, the substrate is then coupled / secured to the housing using a second seal (e.g., by welding and / or brazing with a suitable braze alloy) to form a sensor assembly. In certain embodiments, the substrate can be secured to the housing at its exterior region, as illustrated with sensor assemblies 400, 500, and 600. In certain embodiments, the substrate can be secured to the housing at its middle region in a cantilevered configuration, as illustrated with sensor assemblies 700 and 900. In certain embodiments, the substrate can be inserted into two slots at opposite ends of the housing in an extended configuration and can be coupled / secured to the housing at its middle regions, as illustrated with sensor assembly 800. In some embodiments, the substrate can be secured to the housing at its center region via a face-to-face configuration, as shown with sensor assembly 900. In some embodiments, the substrate can be secured to the adapter / flange at its center region via a face-to-face configuration, and the adapter / flange can be coupled (e.g., welded) to the housing, as shown with sensor assembly 1000 and described in more detail with respect to FIG. 11B .

[0191] In certain embodiments, forming one or more of the metal seals / adhesives described herein (e.g., the first seal, the second seal, the third seal, and any additional metal seals) can include brazing one component to another (e.g., brazing a sensor device to a substrate, brazing the substrate to a housing, or brazing a conductor pin to an electrical contact pad), welding one component to another (e.g., via laser welding or electron beam welding), or bonding one component to another using a metal adhesive formed from a multilayer reactive foil. The brazing alloy used for any of the seals can independently include an Al alloy, an Ag alloy, an Au alloy, a Ni alloy, a Si alloy, an Au-Ni alloy, a Ni-Pd alloy, a Ni-Y alloy, a Ti alloy, or combinations thereof. In certain embodiments, an additional O-ring can be placed between the substrate and the housing (optionally, a cap configured to engage or compress the O-ring can be placed between the substrate and the housing) to enhance the hermetic seal between the substrate and the housing. In some embodiments, the seal provides a hermetic seal to minimize vacuum and / or hermetic leakage from the gas channel 240 to the external environment (e.g., minimizing leakage in the interface between the substrate and the housing, and / or minimizing leakage through a pinhole through which a conductor pin can pass). In some embodiments, one or more of the metal seals / adhesives described herein may include welding one component to another (e.g., by electron beam welding, laser welding, etc.).

[0192] At block 1140, a conformal coating may be deposited onto the sensor assembly to coat at least a portion of the sensor assembly. The coating may be a corrosion-resistant coating. In some embodiments, the conformal coating is a non-conductive material, such as a non-conductive ceramic material. In some embodiments, the conformal coating covers at least a portion of the sensing element 308. In other embodiments, the conformal coating covers the sensor area and does not coat, or only minimally coats, the sensing element. In some embodiments, the coating covers part or all of the substrate (including its interior region, one or more intermediate regions, and one or more exterior regions). In some embodiments, the coating covers part or all of the electrical contact pads on the substrate. In some embodiments, the coating covers part or all of the conductor pins extending from the substrate. In some embodiments, the coating covers part or all of various seals (e.g., seals between the substrate and the sensor device, seals between the substrate and the conductor pins, seals between the conductor pins and the electrical contact pads on the substrate, seals between the substrate and the housing, seals between the substrate and the adapter / flange, and the like). In some embodiments, the sensor assembly is first assembled so that electrical contacts are formed between all components of the sensor assembly (e.g., between the sensor device and the substrate and / or between the substrate and the conductor pins, if present). Thereafter, the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to the airflow when the sensor assembly is coupled to the airflow channel. In some embodiments, the coating deposited on at least a portion of the sensor assembly can be similar to the coating described above as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in deposition technique, coating composition / material, and / or coating uniformity, conformality, porosity, structure, corrosion resistance, and the like). In certain embodiments, the sensor assembly can remain completely uncoated.

[0193] In some embodiments, the conformal coating is deposited using one or more of ALD, IAD, LPPS, CVD, PS-CVD, or sputtering. In some embodiments, the conformal coating comprises a plasma-resistant ceramic coating comprising a rare earth ceramic selected from the group consisting of Y2O3, YZrO, YxZryOz, YZrOF, Y3Al5O12, Y4Al2O9, YF3, YxOyFz, YOF, Er2O3, Er3Al5O12, ErF3, ExOyFz, ErOF, La2O3, Lu2O3, Sc2O3, ScF3, ScOF, Gd2O3, Sm2O3, Dy2O3, a Y2O3-ZrO2 solid solution, ceramics comprising Y2Al4O9 and Y2O3-ZrO2 solid solution, or combinations thereof. In some embodiments, the conformal coating comprises Al2O3. In some embodiments, the conformal coating comprises ALD-deposited Al 2 O 3. In some embodiments, the conformal coating comprises a plurality of layers. In some embodiments, the conformal coating has a thickness of about 10 nm to about 500 nm, or any subrange or single value therein.

[0194] In some embodiments, a method for manufacturing a sensor assembly (e.g., the sensor assembly depicted in FIG. 10D ) follows method 1200, illustrated as a flow chart in FIG. 11B and diagrammatically in FIG. First, according to block 1210, a substrate (e.g., substrate 1002) is provided having an outer region 1002O, an inner region 1002I, and a middle region 1002M positioned between outer region 1002O and inner region 1002I. Thereafter, according to block 1220, a metal flange / adapter 1300 can be secured to the substrate via a first seal 1300A in a parallel, face-to-face arrangement between a substrate-facing side of the flange / adapter 1300 and a first side of the middle region 1002M of the substrate. Thereafter, according to block 1230, a support ceramic ring 1500 can be secured via a second seal 1300B in a parallel, face-to-face arrangement between a substrate-facing side of the support ceramic ring and a housing-facing side of the flange / adapter 1300.

[0195] Thereafter, per block 1240, a sensor device (e.g., sensor device 300) can be secured to the interior region 1002I of the substrate 1002 such that the electrical contacts on the sensor device contact the electrical contact pads on the substrate to establish a continuous and closed electrical circuit for transmitting signals from the sensor device to a processing device (e.g., processing device 230). In some embodiments, the sensor device can be secured to the substrate by forming a third seal 1300C between the electrical contact pads on the substrate and the electrical contacts on the sensor device. The sensor device can be secured to the substrate in a vertical orientation or a parallel orientation.

[0196] Thereafter, according to block 1250, the base plate 1002 (assembled with a metal flange 1300, which is brazed to the base plate on one side and to a ceramic support ring 1500 on the other side) and the sensor device can be inserted into a slot in a housing (e.g., 1004 described above) such that the inner region of the base plate extends from the gas-facing surface of the housing. In certain embodiments, according to block 1250, the metal flange 1300 is then coupled / secured to the housing using a fourth seal 1300D (which can be welded (e.g., electron beam welded), welded, and / or brazed with a suitable braze alloy) to form a sensor assembly (e.g., sensor assembly 1000). In certain embodiments, the base plate can be secured to the housing in a cantilevered configuration at a central region of the base plate. In certain embodiments, the base plate can be inserted into two slots at opposite ends of the housing in an extended configuration and can be coupled / secured to the housing at two central regions of the base plate. In some embodiments, at least a portion of the substrate assembly assembled according to method 1200 may be coated, as described above with respect to block 1140 of method 1100 and throughout this specification with respect to various sensor assemblies. In some embodiments, the substrate assembly assembled according to method 1200 may remain completely uncoated.

[0197] Thereafter, regardless of whether the sensor assembly is manufactured according to method 1100 in FIG. 11A or method 1200 in FIG. 11B , the sensor assembly can be mounted to the airflow channel, attached (e.g., welded) to the tubing, or attached (e.g., via threaded fasteners) to the gas stick assembly, for example, using suitable connectors (e.g., one or more VCR connectors). The sensor assembly can further be connected to one or more external devices (e.g., processing device 230) to form a closed airflow measurement and control circuit. In some embodiments, before connecting the sensor assembly to the one or more external devices, certain portions of the sensor assembly (e.g., the outer portion of the conductor pin in sensor assembly 600) can be at least partially de-coated (e.g., laser etched) to expose conductive portions that can be connected to the external device to form a closed circuit during operation.

[0198] For ease of explanation, the methods of the present disclosure are depicted and described as a series of actions. However, unless otherwise indicated, the actions according to the present disclosure can occur in various orders and / or in parallel, and with other actions not presented and described herein. In addition, not all of the actions shown are required to implement the methods according to the disclosed subject matter. Moreover, those skilled in the art will understand and appreciate that the methods can alternatively be represented as a series of interrelated states via state diagrams or events. Furthermore, it should be understood that the methods disclosed in this specification can be stored on an article of manufacture to facilitate transporting and transferring instructions for performing the methods to a computing device. As used herein, the term "article of manufacture" is intended to encompass a computer program accessible from any computer-readable device or storage medium.

[0199] FIG12A illustrates a cross-sectional side view of a sensor assembly 1201A according to an embodiment of the present disclosure. In some embodiments, sensor assembly 1201A includes a substrate 1202 (e.g., substrate 402, 502, 602, 702, 802, 902, or 1002). The substrate may include electrical contact pads 1214 (e.g., electrical contact pads 414, 514, 614, 714, 814, 914, or 1014). In some embodiments, sensor assembly 1201A includes sensor device 300 coupled (e.g., bonded, adhered, attached, etc.) to substrate 1202 (e.g., at an inner portion of substrate 1202). In some embodiments, substrate 1202 is a ceramic substrate. In some embodiments, substrate 1202 may be a plastic substrate. In some embodiments, substrate 1202 is an insulating substrate. Substrate 1202 may be electrically and / or thermally insulating. In some embodiments, substrate 1202 is a dielectric substrate. Substrate 1202 may be a multilayer ceramic substrate, a PCB substrate, or a ceramic substrate. In some embodiments, substrate 1202 may include a PCB ceramic coating. In some embodiments, substrate 1202 may include a PCB insulating polymer (e.g., polyimide). As described above and below with reference to FIG. 12B , substrate 1202 may be joined to adapter / flange 1300 by brazing (e.g., using a suitable brazing alloy), welding, and / or another technique. In some embodiments, adapter / flange 1300 is coupled to housing 1204 (e.g., housing 704, 904, or 1004) via one or more screws 1278. Screws 1278 may be threaded fasteners (e.g., screws, bolts, etc.). An O-ring 1280 may be disposed between adapter / flange 1300 and the top surface of housing 1204. Screws 1278 may be tightened to seal adapter / flange 1300 to housing 1204. When screw 1278 is tightened, O-ring 1280 may be compressed and form an airtight seal.

[0200] FIG12B illustrates a cross-sectional side view of sensor assembly 1201B, according to an embodiment of the present disclosure. In some embodiments, adapter / flange 1300 is brazed to housing 1204 along braze line 1203. As described above, adapter / flange 1300 can be brazed using a suitable braze alloy. Adapter / flange 1300 can be brazed to housing 1204 to form a hermetic seal.

[0201] Figure 13A illustrates a cross-sectional side view of an adapter / flange, a multilayer ceramic substrate, and a sensor device according to an embodiment of the present disclosure. Figure 13B illustrates an exploded cross-sectional side view of an adapter / flange, a multilayer ceramic substrate, and a sensor device according to an embodiment of the present disclosure.

[0202] Substrate 1302 (e.g., substrate 402, 502, 602, 702, 802, 902, or 1002) can be coupled to flange 1399 (e.g., adapter / flange 1300). In some embodiments, flange 1399 includes a recess 1303 to receive features of substrate 1302. Recess 1303 can be a circular recess formed in a surface of flange 1399 to position substrate 1302 so that sensor device 300 is positioned at a predetermined location in a gas tube (e.g., a gas tube of housing 704, 904, or 1004). Recess 1303 can prevent substrate 1302 from moving relative to flange 1399. Substrate 1302 can be inserted through a hole in flange 1399 until the features of substrate 1302 lock into recess 1303. In some embodiments, substrate 1302 can be configured to couple to a gas flow tube (e.g., via flange 1399).

[0203] Figures 14A-14D illustrate various alignment features that can be used to position, align, and / or orient a sensor device relative to a substrate in embodiments. In embodiments, the sensor features can ensure that the sensor device has a desired orientation (e.g., rotation, tilt, etc.) and position relative to the substrate in one or more planes. In embodiments, these alignment features can be used with any of the sensor assemblies shown in Figures 4A-10D.

[0204] FIG14A illustrates a side view of a substrate 1402 (e.g., a ceramic substrate) and sensor device 1401 after the sensor device 1401 has been positioned and oriented relative to the substrate 1402 for bonding, according to an embodiment of the present disclosure. FIG14B illustrates an exploded side view of the substrate 1402 and sensor device 1401 before positioning the sensor device 1401 relative to the substrate 1402, according to an embodiment of the present disclosure. FIG14A-14B show a system 1400 for aligning and / or attaching the sensor device 1401 to the substrate 1402, according to an embodiment of the present disclosure. As shown in FIG14A-B , the sensor device 1401 is oriented such that the sensor face of the sensor device 1401 is orthogonal to the direction of the airflow 1450, where the airflow is in the X direction.

[0205] Sensor device 1401 may correspond to sensor device 300 and may be coupled (e.g., attached, bonded, etc.) to substrate 1402 (which may correspond, for example, to substrates 402, 502, 602, 702, 802, 902, or 1002) using one or more alignment features. The one or more alignment features may align sensor device 1401 relative to substrate 1402 in a first plane and / or a second plane (e.g., a first plane parallel to the airflow through the sensor assembly housing and / or perpendicular to the interface between sensor device 1401 and substrate 1402, and a second plane substantially perpendicular to the first plane, e.g., parallel to the interface between sensor device 1401 and substrate 1402). In some embodiments, the one or more alignment features cause sensor device 1401 to be positioned at a target location on substrate 1402 such that the sensor die is centered in the gas channel during use. In some embodiments, the one or more alignment features cause sensor device 1401 to be positioned such that sensor device 1401 is substantially deterministically positioned within the gas channel during use of the sensor assembly. In one embodiment, the first plane in which the orientation of sensor device 1401 relative to substrate 1402 is controlled is the XY plane as shown in Figures 14A-B. Thus, the alignment features of the sensor device and the substrate can control the tilt of the sensor device within the XY plane relative to the direction of gas flow.

[0206] In some embodiments, as shown in FIG14A , the alignment features include one or more alignment features 1412 (e.g., one or more protrusions) extending from the sensor device 1401 and one or more corresponding recesses or holes in the substrate that are positioned and shaped to receive the one or more protrusions. The alignment features may additionally or alternatively include one or more recesses or holes in the sensor device 1401 and corresponding protrusions in the substrate that are configured to fit into the one or more recesses or holes. The alignment features may additionally or alternatively include one or more alignment marks 1422 that can be used by a technician or a vision-assisted robotic arm to position and orient the sensor device 1401 relative to the substrate 1402.

[0207] In some embodiments, the alignment feature additionally or alternatively includes a recess or notch 1420 in the substrate that is shaped to receive a portion of the sensor device 1401. For example, as shown in Figures 14A-14B, one end and a portion of both sides of the sensor device 1401 fit snugly into the recess 1420. The recess 1420 can provide stability to the sensor device 1401, can limit the degrees of freedom of possible positions / orientations of the sensor device 1401 relative to the substrate 1402, and / or can control the positioning of the sensor device 1401 on the substrate 1402 (e.g., to ensure that the sensor device 1401 is centered in a plane orthogonal to the direction of gas flow when the sensor assembly is installed in a gas assembly or gas pipeline).

[0208] In some embodiments, sensor device 1401 includes alignment features 1412, and substrate 1402 includes alignment features 1414. Together, these alignment features align sensor device 1401 relative to substrate 1402. Alignment features 1412 and 1414 can control the tilt of sensor device 1401 relative to substrate 1402 within a first plane parallel to the interface between sensor device 1401 and substrate 1402. In some embodiments, alignment feature 1412 includes a ridge / protrusion, and alignment feature 1414 includes a corresponding groove / hole / recess to receive the ridge / protrusion of alignment feature 1412. In some embodiments, alignment feature 1412 includes a substantially cylindrical protrusion, and alignment feature 1414 includes a corresponding cylindrical hole to receive the cylindrical protrusion. In some embodiments, alignment feature 1412 includes a conical protrusion, and alignment feature 1414 includes a corresponding conical hole to receive the conical protrusion. Using conical protrusions and holes can simplify the process of placing alignment feature 1412 into alignment feature 1414. In some embodiments, alignment feature 1412 and alignment feature 1414 have square, rectangular, trapezoidal, circular, oval, spherical, dome-shaped, or other shapes. In some embodiments, the shape of alignment feature 1412 is the negative of the shape of alignment feature 1414, or the shape of alignment feature 1414 is the negative of the shape of alignment feature 1412, so that the mating of alignment feature 1412 and alignment feature 1414 can be controlled. In some embodiments, the alignment features can be internal and / or external to substrate 1402 and / or sensor device 1401. In some embodiments, alignment feature 1414 is machined into substrate 1402 using a computer-controlled machining process. Alignment feature 1414 can be drilled or milled into the surface of substrate 1402. In some embodiments, alignment feature 1412 can be bonded to a box 1416 (e.g., a plastic box).

[0209] In some embodiments, two pairs of opposing alignment features are used (e.g., first pair of alignment features 1412 and corresponding alignment features 1414, and second pair of alignment features 1412 and corresponding alignment features 1414). In one embodiment, at least three pairs of opposing alignment features are used (e.g., first pair of alignment features 1412 and corresponding alignment features 1414, second pair of alignment features 1412 and corresponding alignment features 1414, and third pair of alignment features 1412 and corresponding alignment features 1414).

[0210] In some embodiments, sensor device 1401 includes one or more lateral protrusions 1410 extending laterally from sensor device 1401. In embodiments, lateral protrusions 1410 may extend in a plane parallel to a top surface of sensor device 1401. In embodiments, the lateral protrusions may each include one or more alignment features (e.g., at their distal ends) that extend orthogonally to the plane parallel to the top surface of sensor device 1401.

[0211] As previously described, sensor device 1401 can be formed, for example, from silicon or another material. Sensor device 1401 can be connected to a case 1416 (e.g., a plastic case), and alignment features 1412 and / or lateral protrusions 1410 can be coupled to case 1416. In one example, lateral protrusions 1410 can be posts coupled to case 1416 of sensor device 1401 to align sensor device 1401 relative to substrate 1402. In some embodiments, protrusions 1410 can be metal protrusions bonded to case 1416. In some embodiments, protrusions 1410 are machined using a computer-controlled machining process. Similarly, protrusions 1410 can be bonded to case 1416 using a computer-controlled robotic and bonding process. In some embodiments, after bonding the sensor device to substrate 1402, the case can be removed from sensor device 1401. As shown, in some embodiments, each of the transverse protrusions 1410 can include an alignment feature 1412 at the distal end of the transverse protrusion. Alignment feature 1414 can be configured to receive a corresponding alignment feature 1412 attached to transverse protrusion 1410. In some embodiments, alignment feature 1414 can be configured to receive a corresponding protrusion (e.g., a protrusion of alignment feature 1412). Each of alignment features 1412 can be received by an alignment feature 1414 formed in substrate 1402. In some embodiments (e.g., as shown in FIG. 14A-B ), sensor device 1401 can include three transverse protrusions 1410, each having a corresponding alignment feature 1412, and substrate 1402 includes three corresponding alignment features 1414. However, in some embodiments, system 1400 can include more or fewer transverse protrusions 1410, alignment features 1412, and / or alignment features 1414. Fitting each of the alignment features 1412 into the alignment features 1414 can cause the sensor device to be aligned in a first plane (e.g., the plane of the page as shown). In response to each of the alignment features 1412 being inserted into the corresponding alignment feature 1414, the sensor device 1401 can be substantially prevented from moving (e.g., moving laterally, tilting, etc.) along a plane (e.g., the plane of the page as shown).

[0212] In some embodiments, substrate 1402 includes one or more alignment marks (e.g., visual alignment features) 1422. Alignment marks 1422 can provide visual cues for the alignment of sensor device 1401 relative to substrate 1402 within a first plane. In one embodiment, alignment marks 1422 include L-shaped marks that indicate where the corners of sensor device 1401 should be positioned. A technician (e.g., an operator, engineer, assembler, etc.) or an assembly robot (e.g., via an imaging sensor) can verify the alignment of sensor device 1401 relative to alignment marks 1422 within the first plane. In some embodiments, alignment marks 1422 are engraved on substrate 1402. In some embodiments, marks 1422 are engraved on sensor device 1401.

[0213] FIG14C illustrates a cross-sectional view of a substrate (e.g., a ceramic substrate) 1404 mated with a sensor device 1403, according to an embodiment of the present disclosure. FIG14D illustrates an exploded cross-sectional view of the substrate 1404 and sensor device 1403, according to an embodiment of the present disclosure. FIG14C-14D show views perpendicular to the views shown in FIG14A-B. As shown, FIG14A-14B are in the XY plane, while FIG14C-14D are in the XZ plane. As shown, a set of alignment features 1418 (e.g., posts or protrusions) on the substrate 1404 are inserted into a set of alignment features 1417 (e.g., holes or recesses) on the sensor device 1403. The set of alignment features 1417 and the set of alignment features 1418 are configured to substantially fix the sensor device 1403 relative to the substrate 1404 in a first plane (e.g., the XY plane) in response to the set of alignment features 1417 receiving the set of alignment features 1418.

[0214] Although sensor device 1401 is described above as including one or more protrusions and substrate 1402 is described as including one or more corresponding holes, it is contemplated that in some embodiments, substrate 1402 may also include one or more protrusions to be inserted into one or more alignment holes formed in sensor device 1401. Similarly, although substrate 1404 is described above as including one or more protrusions and sensor device 1403 is described as including one or more corresponding holes, it is contemplated that in some embodiments, sensor device 1403 may also include one or more protrusions to be inserted into one or more alignment holes formed in substrate 1404.

[0215] Figures 15A-15D illustrate various alignment features that can be used to position, align, and / or orient a sensor device relative to a substrate in embodiments. In embodiments, the sensor features can ensure that the sensor device has a desired orientation (e.g., rotation, tilt, etc.) and position relative to the substrate in one or more planes. These alignment features can be used with any of the sensor assemblies of Figures 4A-10D in embodiments and can be combined with the alignment features of Figures 14A-14D in embodiments.

[0216] Figures 15A-G illustrate a system for bonding a sensor device to a substrate 1502 (e.g., a ceramic substrate) according to an embodiment of the present disclosure. In some embodiments, sensor device 1503 can correspond to sensor device 300 and / or can be bonded to substrate 1502 (e.g., substrates 402, 502, 602, 702, 802, 902, or 1002) by soldering, brazing, fusing, welding, flash bonding (e.g., using a multilayer reactive foil), or any combination thereof. Specifically, electrodes 1515 (e.g., electrical contacts) of sensor device 1503 can be bonded to electrical contact pads 1514 of substrate 1502. Electrodes 1515 can be bonded to electrical contact pads 1514 as described below. In some embodiments, one or more alignment features (e.g., solder 1518, electrodes 1515, electrical contact pads 1514) can be used to align sensor device 1503 with substrate 1502. For embodiments where direct contact is made between the contact pads and the electrodes, the alignment features may include contact pads / electrodes on the sensor device and / or the substrate itself. The alignment features may additionally or alternatively include carefully controlled solder joints (e.g., having a uniform thickness) for bonding the contact pads to the electrodes. In embodiments, the alignment features may be used to control the orientation and / or tilt of the sensor device 1503 relative to the substrate 1502 in a plane perpendicular to the interface between the sensor device and the substrate (e.g., in the XZ plane).

[0217] Referring to FIG. 15A , a system 1501A for bonding a sensor device 1503 to a substrate 1502 is shown, according to an embodiment of the present disclosure. In some embodiments, a quantity of solder 1518 (e.g., solder bumps) may be placed on each of the electrical contact pads 1514. Solder 1518 may be generally spherical when placed on the electrical contact pads 1514. The top surface of solder 1518 may then be flattened by a coining operation to create a substantially cylindrical shape. The coining operation may flatten solder 1518 to a controlled thickness. In some embodiments, the coining operation may flatten each solder bump in a plurality of solder bumps to a controlled thickness that is substantially similar to the controlled thickness of the remaining solder bumps in the plurality of solder bumps. Next, sensor device 300 may be placed on substrate 1502 such that electrode 1515 contacts the flattened solder 1518. Solder 1518 can then be bonded to electrode 1515 to form a solder joint between sensor device 300 and substrate 1502. Solder 1518 can form a joint that couples electrode 1515 to electrical contact pad 1514. Because the solder joints have a uniform thickness, tilting of the sensor device relative to the substrate can be controlled or minimized. For example, due to the use of alignment features (e.g., coined solder bumps 1518), sensor device 1503 can be aligned parallel to substrate 1502. The one or more alignment features discussed with respect to Figures 14A-D can further include solder joints as described above. In some embodiments, the solder joints can align sensor device 300 within a second plane (e.g., the XZ plane).

[0218] Referring to FIG. 15B , a system 1501B for bonding a sensor device 1503 to a substrate 1502 is shown, according to an embodiment of the present disclosure. In some embodiments, the sensor device 1503 is placed in a jig 1512 . In some embodiments, the substrate 1502 is placed in the jig 1512 . The jig 1512 can have a recess to receive the sensor device 1503 . In some embodiments, the jig 1512 includes a vacuum port 1504 . A vacuum can be applied at the vacuum port 1504 to secure the sensor device 1503 in the jig 1512 during a bonding process (e.g., a bonding process described herein). The sensor device 1503 can be placed in the jig 1512 such that the electrode 1515 is exposed (e.g., facing upward, as shown). The substrate 1502 can be placed on the sensor device 1503 . In some embodiments, the substrate 1502 has a through-hole 1516 formed therein. Electrical contact pads 1514 can extend from the surface of substrate 1502 into each through-hole 1516. Through-holes 1516 can be aligned with electrodes 1515. In some embodiments, substrate 1502 forms two through-holes 1516, and the sensor device includes two electrodes 1515. Each through-hole 1516 can be aligned with one of the two electrodes 1515. Substrate 1502 can be placed on (e.g., adjacent to) sensor device 1503. Solder 1518 can be placed in through-holes 1516 to at least partially fill them. In some embodiments, solder 1518 at least partially fills through-holes 1516. Solder 1518 can make electrical contact between electrodes 1515 and electrical contact pads 1514. Solder 1518 can form solder joints between substrate 1502 and sensor device 1503. In some embodiments, the one or more alignment features described above comprise the solder joints discussed herein. The solder joints discussed herein may enable alignment of the sensor device 1503 within the second plane.

[0219] Referring to FIG. 15C , a system 1501C for bonding a sensor device to a substrate is shown, according to an embodiment of the present disclosure. In some embodiments, electrical contact pads 1514 may be disposed between two layers of substrate 1502. In such embodiments, electrical contact pads 1514 may be exposed within the inner surface of through-hole 1516. Furthermore, in some embodiments, a lamination layer 1526 may be deposited over solder 1518. Lamination layer 1526 may be deposited on a portion of the surface of substrate 1502 near through-hole 1516. In some embodiments, lamination layer 1526 may be a conformal coating, as described above. Lamination layer 1526 may be an anti-corrosion layer to protect solder 1518 and / or the joint formed between sensor device 300 and substrate 1502. Solder 1518 may form a solder joint between substrate 1502 and sensor device 1503. In some embodiments, the one or more alignment features described above comprise the solder joints discussed herein. The solder joints discussed herein may enable alignment of the sensor device 1503 within the second plane.

[0220] Referring to FIG. 15D , a system 1501D for bonding a sensor device to a substrate is shown, according to an embodiment of the present disclosure. In some embodiments, an electrical contact pad 1514 of substrate 1502 can be placed in contact with an electrode 1515 of sensor device 1503. In some embodiments, radiation from a welder can be directed toward a metal contact region formed by electrical contact pad 1514 and electrode 1515. The metal contact region can be irradiated with radiation 1524 to create a fused joint 1522 (e.g., via ultraviolet, infrared, or CO₂ laser radiation). In some embodiments, a laser beam can be used to irradiate electrical contact pad 1514 and electrode 1515. The irradiated electrical contact pad 1514 and electrode 1515 can be heated and at least partially melted by radiation 1524. Electrical contact pad 1514 and electrode 1515 can fuse as they cool. In some embodiments, the metal contact region functions as one of the one or more alignment features described above. In some embodiments, the fused joint between the electrical contact pad and the electrode functions as one of the one or more alignment features described above.

[0221] In some embodiments, to facilitate fusing electrical contact pads 1514 and electrodes 1515 by irradiation (e.g., via emitted radiation 1524), substrate 1502 and / or sensor device 1503 are substantially transparent to the wavelength of radiation 1524 used. For example, substrate 1502 may be substantially transparent to a laser beam of a given wavelength used to fuse electrical contact pads 1514 and electrodes 1515. As used herein, "substantially transparent" means that at least approximately 80% or at least 90% or more of radiation 1524 is transmitted through substrate 1502 and / or sensor device 1503 (e.g., up to 20% absorption). In some embodiments, substrate 1502 may be made of glass, quartz, or a silicate material. In such embodiments, substrate 1502 may be sufficiently transparent to the wavelength of radiation 1524 emitted from the radiation source to heat electrical contact pads 1514 and electrodes 1515 to a melting point. In some embodiments, the transparency of substrate 1502 and / or sensor device 1503 may be increased by reducing reflections. In some embodiments, the surfaces of substrate 1502 and sensor device 1503 may be textured to increase transparency.

[0222] In some embodiments, electrical contact pad 1514 and electrode 1515 are made of different metals. In other embodiments, electrical contact pad 1514 and electrode 1515 are made of the same metal (e.g., platinum). In some embodiments, electrical contact pad 1514 and electrode 1515 are made of metals that can be compatible with each other as described above.

[0223] Referring to FIG. 15E , a system 1501E for bonding a sensor device 1503 to a ceramic substrate 1502 is shown, according to an embodiment of the present disclosure. In some embodiments, the electrical contact pad 1514 and the electrode 1515 are bonded using a metal adhesive. As described above, in some embodiments, the electrical contact pad 1514 and the electrode 1515 comprise a platinum conductor. The metal adhesive can include one or more layers of a metal selected from platinum, tin, indium, copper, aluminum, and / or nickel. In some embodiments, the metal adhesive comprises a metal that is corrosion-resistant and / or chemically compatible with the gas flowing through the sensor assembly of which the substrate 1502 and the sensor device 1503 are part. In some embodiments, the metal adhesive comprises one or more metal adhesive layers. In one embodiment, each metal adhesive layer can comprise aluminum and / or nickel. The metal adhesive provides an electrical connection between the electrode 151 and the electrical contact pad 1514.

[0224] The metal bond can mechanically bond the electrical contact pad 1514 and the electrode 151 and can be produced using a multilayer reactive foil 1519. In one embodiment, a layer of metal bonding material comprising aluminum and / or nickel is used. Alternatively, other metals can be used. Furthermore, the metal bond can include a thin layer of aluminum and / or nickel (having a thickness of, for example, approximately 2-4 mils in one embodiment) between two other metal layers (e.g., between two tin layers). In one embodiment, the thin layer is initially a reactive multilayer foil (referred to herein as reactive foil) composed of alternating nanoscale layers of reactive materials such as aluminum and nickel. During a room-temperature metal bonding process, the reactive foil can be activated (e.g., ignited), resulting in a nearly instantaneous reaction, generating temperatures exceeding 1500 degrees Celsius. This causes the upper and lower metal layers, acting as solder, to melt and reflow, bonding the electrode 1515 to the electrical contact pad 1514. In one embodiment, the reactive foil is NanoFoil® manufactured by Indium Corporation of the United States.

[0225] In one example, foil 1519 can include alternating layers of a nickel alloy and an aluminum alloy. Foil 1519 can be cut into tabs and positioned between electrical contact pad 1514 and electrode 1515. During the manufacturing process, as discussed below with reference to FIG. 16B , in some embodiments, foil 1519 can be ignited (e.g., by applying an electric current to foil 1519) to cause foil 1519 to reactively bond to both electrical contact pad 1514 and electrode 1515. For example, a voltage can be applied to foil 1519 to induce an electric current through foil 1519, causing foil 1519 to reactively bond and conform to the shape of electrical contact pad 1514 and / or electrode 1515. In some embodiments, the bond resulting from the reactively bonded foil 1519 is a conductive bond between electrical contact pad 1514 and electrode 1515. In some embodiments, an anti-corrosion coating is provided on the exposed portions of the bond. The anti-corrosion coating may be a perfluoropolymer single layer coating, a silane-based coating (eg, a fluorinated alkylsilane coating, a perfluorooctylitriethoxysilane coating, etc.), or an inorganic oxide coating.

[0226] Referring to FIG. 15F , a system 1501F for bonding a sensor device to a ceramic substrate is shown, according to an embodiment of the present disclosure. In some embodiments, a metal adhesion layer 1517 is deposited onto electrical contact pads 1514 and / or electrodes 1515. In some embodiments, one or more metal adhesion layers 1517 are deposited onto electrical contact pads 1514 and / or electrodes 1515. Metal adhesion layer 1517 can facilitate bonding a multilayer reactive foil 1519 to electrical contact pads 1514 and / or electrodes 1515. In some embodiments, metal adhesion layer 1517 can be an aluminum alloy layer or a nickel alloy layer. Foil 1519 can be placed on metal adhesion layer 1517 of either electrical contact pads 1514 or electrodes 1515 prior to bonding. Electrical contact pads 1514 and electrodes 1515 can be bonded via multilayer reactive foil 1519, as described above with reference to FIG. 15E .

[0227] Referring to FIG. 15G , a system 1501G for bonding a sensor device 1503 to a substrate 1502 is shown, according to an embodiment of the present disclosure. In some embodiments, the sensor device 1503 can be bonded to the substrate 1502 via one or more welded joints. For example, the sensor device 1503 can be welded to the substrate 1502 (e.g., via the electrodes 1515 and the electrical contact pads 1514). A metal wire 1521 (e.g., a platinum wire) can be welded to each electrode 1515. The metal wire 1521 can be welded to each electrode 1515 via a welding operation (e.g., an electron beam welding operation or a laser welding operation). Alternatively, the electrodes 1515 can be metal wires (e.g., platinum wires) extending from the sensor device 1503. The sensor device 1503 can be placed on the substrate 1502 such that at least a portion of the metal wire 1521 overlies the corresponding electrical contact pad 1514. The metal wire 1521 can be welded to the electrical contact pad 1514 by another welding operation (such as electron beam welding or laser beam welding). The metal wire 1521 welded to the electrical contact pad 1514 and / or the electrode 1515 can bond the sensor device 300 to the substrate 1502.

[0228] In some embodiments, bonded joints (e.g., solder joints, fused joints, welded joints, etc.) formed by the processes and methods described with reference to FIG15A-G are included with the one or more alignment features described above. The bonded joints can align and / or secure the sensor device 300 relative to the substrate 1502 in the first plane and the second plane.

[0229] 16A-C illustrate a flow chart of a method for manufacturing a sensor assembly according to an embodiment of the present disclosure. Referring to FIG16A , a flow chart of a method 1600A for manufacturing a sensor assembly according to an embodiment of the present disclosure is shown.

[0230] At block 1602, in some embodiments, a substrate is provided having an outer region, an inner region, and a middle region. The substrate may further include one or more electrical contact pads located at least on the inner region. The substrate may be a multilayer ceramic substrate.

[0231] At block 1604, in some embodiments, a sensor die (e.g., sensor device 300) is coupled to a substrate via one or more alignment features that align the sensor die relative to the substrate in at least one of a first plane or a second plane. The one or more alignment features can be protrusions (e.g., lateral protrusions 1410 of FIG. 14A-D ), alignment marks (e.g., visual alignment features, such as visual alignment features 1422 of FIG. 14A-14B ), and / or one or more adhesives (e.g., metal adhesive, fusion adhesive, solder adhesive, weld adhesive, etc.). In some embodiments, at block 1606, a first set of protrusions protruding from the sensor die is inserted into a first set of alignment holes (e.g., alignment holes of FIG. 14A-D ) formed in the substrate. In some embodiments, the first set of protrusions protrudes from a plastic box (e.g., box 1416 of FIG. 14A and B ) bonded to the sensor device. The sensor device may then be bonded to the substrate while alignment features (eg, protrusions, solder bumps, etc.) of the sensor device engage alignment features (eg, holes, solder bumps, etc.) of the substrate.

[0232] At block 1608, in some embodiments, the substrate is coupled to the housing at an outer region of the substrate to provide a hermetic seal. As described above, the substrate can be welded and / or brazed to the housing. In some embodiments, the substrate can be coupled to the housing via a flange (e.g., flange / adapter 1300).

[0233] Referring to FIG. 16B , a flow chart of a method 1600B for manufacturing a sensor assembly is shown, according to an embodiment of the present disclosure. In some embodiments, at block 1612, a substrate is provided. The substrate may have an outer region, an inner region, and a middle region. The substrate may further include one or more electrical contact pads located at least on the inner region. At block 1614, in some embodiments, a sensor die (e.g., sensor device 300) is provided. The sensor die may have one or more electrodes.

[0234] At block 1616, in some embodiments, a multilayer reactive foil is disposed on each of the one or more electrical contact pads of the substrate and / or the electrodes of the sensor die. The multilayer reactive foil may include alternating layers of two reactive metals (e.g., nickel and aluminum). In some embodiments, a metal adhesion layer (e.g., an aluminum alloy layer or a nickel alloy layer) is deposited on the electrical contact pads and / or electrodes before disposing the multilayer reactive foil on the one or more electrical contact pads and / or electrodes.

[0235] At block 1618, in some embodiments, the sensor die is positioned on the interior region of the substrate such that the multilayer reactive foil is sandwiched between the one or more electrical contact pads and the one or more electrodes. At block 1620, in some embodiments, the multilayer reactive foils can be ignited to form a metal bond between the one or more electrical contact pads of the substrate and the one or more electrodes of the sensor die. In some embodiments, the multilayer reactive foil can be ignited by inducing an electrical current through the foil (e.g., by applying a voltage to the foil). The metal bonding process using the reactive multilayer foil can be a room temperature metal bonding process, in which the reactive foil can be activated (e.g., ignited) to create a near-instantaneous reaction at the interface of the two surfaces to be bonded, producing temperatures exceeding 1500 degrees Celsius. This can cause upper and lower metal layers (e.g., metal bond layers), which can act as solder, to melt and reflow, bonding the electrodes to the electrical contact pads.

[0236] In some embodiments, after the metal bonding process is completed (eg, via ALD, CVD, etc.), an anti-corrosion coating (eg, as discussed above) is deposited on at least the exposed portions of the metal bond.

[0237] At block 1622, in some embodiments, the substrate is coupled to the housing at an exterior region to provide a hermetic seal. As described above, the substrate can be welded and / or brazed to the housing. In some embodiments, the substrate can be coupled to the housing via a flange (e.g., flange / adapter 1300).

[0238] Referring to FIG. 16C , a flow chart of a method 1600C for manufacturing a sensor assembly is shown, according to an embodiment of the present disclosure. In some embodiments, at block 1632 , a substrate is provided. The substrate may have an outer region, an inner region, and a middle region. The substrate may further include one or more electrical contact pads located at least on the inner region. At block 1634 , in some embodiments, a sensor die (e.g., sensor device 300 ) is provided. The sensor die may include one or more electrodes.

[0239] At block 1636, in some embodiments, a metal wire may be bonded to each of the one or more electrodes by a first welding operation. In some embodiments, the one or more electrodes comprise platinum, and the metal wire may be a platinum wire. The first welding operation may be a laser welding operation or an electron beam welding operation. The first end of the metal wire may be bonded to each electrode by the welding operation. In some embodiments, the electrodes themselves are metal wires extending from the sensor device, and therefore block 1636 may be skipped.

[0240] At block 1638, in some embodiments, the sensor die is positioned on the interior region of the substrate such that at least a portion of the metal wire or electrode overlies a corresponding electrical contact pad of the one or more electrical contact pads. At block 1640, in some embodiments, the metal wire is bonded to the corresponding electrical contact pad by a second welding operation (or first welding operation if the electrode is a metal wire). The welding operation can be a laser welding operation or an electron beam welding operation. In some embodiments, the welding operation includes welding along a first side of the metal wire and a second side of the metal wire. The welding operation can bond the corresponding metal wire to the corresponding electrical contact pad.

[0241] At block 1642, in some embodiments, the substrate is coupled to the housing at an exterior region to provide a hermetic seal. As described above, the substrate can be welded and / or brazed to the housing. In some embodiments, the substrate can be coupled to the housing via a flange (e.g., flange / adapter 1300).

[0242] Figures 16D-F illustrate a flow chart of a method for bonding a sensor device to a substrate, according to an embodiment of the present disclosure. Referring to Figure 16D, a flow chart of method 1600D for bonding a sensor device to a substrate, according to an embodiment of the present disclosure, is illustrated. At block 1652, in some embodiments, a first solder bump is placed on a first electrical contact pad (e.g., an electrical contact pad of the substrate). At block 1654, in some embodiments, a second solder bump is placed on a second electrical contact pad. The first solder bump and the second solder bump may include a first amount of solder. In some embodiments, the first solder bump and the second solder bump are substantially spherical.

[0243] At block 1656, in some embodiments, the block includes the following steps: flattening the top surface of each of the first and second solder bumps by a coining process. The coining process may form each of the first and second solder bumps into a substantially cylindrical shape. The coined solder bumps may each have the same or substantially the same size and / or thickness. At block 1658, in some embodiments, first and second electrodes of the sensor die are placed on the top surfaces of the flattened first and second solder bumps to bond the sensor die to the substrate. In some embodiments, the sensor die is placed on the substrate by an end effector of a robotic arm (e.g., a robotic arm of a manufacturing robot). Electrical connectivity may be established between the sensor die and the substrate via the electrical contact pads, the solder bumps, and the electrodes. Soldering or welding may then be performed to bond the electrical contact pads to the electrodes using the solder bumps.

[0244] Referring to FIG16E , a flow chart illustrating a method 1600E for bonding a sensor device to a substrate is shown, according to an embodiment of the present disclosure. At block 1662 , in some embodiments, a sensor die is placed in a fixture. The first and second electrodes of the sensor die may be exposed in response to the sensor die being placed in the fixture. For example, the sensor die may be placed in a recess of the fixture with the electrodes facing upward (e.g., as shown in FIG15B ).

[0245] At block 1664, in some embodiments, a first through-hole and a second through-hole formed in the substrate are aligned with the first electrode and the second electrode, respectively. At block 1666, the substrate can be placed adjacent to (e.g., on) the sensor die. In some embodiments, the substrate is placed on the sensor die using an end effector of a robotic arm (e.g., a robotic arm of a manufacturing robot).

[0246] At block 1668, in some embodiments, the first through-hole and the second through-hole are each filled with a first amount of solder to bond the sensor die to the substrate. In some embodiments, the first amount of solder may at least partially fill the first through-hole and the second through-hole. The solder may establish electrical connectivity between the sensor die and the substrate via the electrodes and the electrical contact pads.

[0247] At block 1670, in some embodiments, a lamination layer is deposited over the solder. The lamination layer can protect the solder from harmful environmental chemicals present when the sensor assembly is in use, such as in the system described with reference to FIG. 1 . The lamination layer can be deposited over the solder and at least a portion of the substrate surface adjacent to the first through-hole and the second through-hole.

[0248] Referring to FIG. 16F , a flow chart illustrating a method 1600F for bonding a sensor device to a substrate is shown, according to an embodiment of the present disclosure. At block 1672 , in some embodiments, a sensor die is placed on the substrate, with the electrodes of the sensor die resting on electrical contact pads of the substrate. In some embodiments, the sensor die is placed using an end effector of a robotic arm (e.g., a robotic arm of a manufacturing robot).

[0249] At block 1674, in some embodiments, the electrodes and / or electrical contact pads are irradiated to fuse the electrodes to the electrical contact pads. In some embodiments, the electrodes and / or electrical contact pads are irradiated with a radiation source. The radiation source can be a laser radiation source, a UV radiation source, and / or an infrared radiation source. In some embodiments, the radiation source is a CO2 laser. In some embodiments, the sensor die and / or substrate is made of a material that is substantially transparent to a predetermined wavelength of radiation, as described above with reference to FIG. 15D . Fusion of the electrodes and electrical contact pads can establish electrical connectivity between the sensor die and the substrate via the electrodes and electrical contact pads.

[0250] For ease of explanation, the methods of the present disclosure are depicted and described as a series of actions. However, unless otherwise indicated, the actions according to the present disclosure may occur in various orders and / or in parallel, and in conjunction with other actions not presented and described herein. Furthermore, not all of the actions shown are required to implement the methods according to the disclosed subject matter. Furthermore, those skilled in the art will understand and appreciate that methods may alternatively be represented as a series of interrelated states via state diagrams or events. Furthermore, it should be understood that the methods disclosed in this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring instructions for performing the methods to a computing device. As used herein, the term "article of manufacture" is intended to encompass a computer program accessible from any computer-readable device or storage medium.

[0251] In some embodiments, a sensor assembly comprising a substrate, a sensor die / sensor device, and a housing includes one or more channels that provide an airflow path. In such embodiments, the housing may not be secured to the gas conduit to extend the sensor die / sensor device into the airflow path within the gas conduit. Instead, the airflow path may be diverted through the one or more channels of the sensor assembly and then returned to the gas conduit. An example of a sensor assembly configuration that includes its own channels to provide an airflow path is a sensor assembly designed for use with a gas stick assembly. The sensor assembly can be configured to fit within a standard mount on the base of a gas stick assembly (e.g., a mount that typically receives a valve, filter, or other component for a gas stick assembly). In such embodiments, the substrate can be disposed within at least a portion of the housing, and the sensor device / sensor die coupled to the substrate can be positioned within the housing's internal channel. In some embodiments, the sensor device / sensor die is positioned at the center of a cross-section of the channel within the housing.

[0252] 17A-17H illustrate embodiments of sensor assemblies that may be used on a gas wand assembly.

[0253] FIG17A illustrates a perspective view of a sensor assembly 1700A according to an embodiment of the present disclosure. FIG17B illustrates a front view of section EE in FIG17A. FIG17C illustrates a front view of section EE in FIG17A. FIG17D illustrates a front view of section FF in FIG17A.

[0254] In some embodiments, sensor assembly 1700A includes a housing 1708. In some embodiments, housing 1708 is made of a stainless steel alloy. Alternatively, housing 1708 can be made of any housing material discussed elsewhere herein. Housing 1708 can be substantially cubic in shape, or it can have a cylindrical or other shape. Housing 1708 can include one or more holes for mounting on the base of a gas stick assembly (e.g., a mount on the base of a gas stick assembly (e.g., gas stick assembly 1750 in Figures 17H-I)). Furthermore, the one or more holes for mounting can be configured to couple housing 1708 to an auxiliary component. The bottom surface of sensor assembly 1700A can be sealed to the base or mount of the gas stick assembly, and the top surface of sensor assembly 1700A can optionally be sealed to an auxiliary component (e.g., a filter or valve). These holes can be configured to receive fasteners (e.g., screws or bolts) to secure sensor assembly 1700A to the gas stick assembly. The top and bottom surfaces of the housing 1708 may include one or more grooves or recessed areas configured to receive a sealing component (e.g., a metal seal). Once the housing 1708 is secured to the base of the gas stick assembly and / or the auxiliary component via the fasteners, the sealing component may be compressed and a seal may be formed between the housing 1708 and the base of the gas stick assembly and / or between the housing 1708 and the auxiliary component.

[0255] Housing 1708 may include one or more gas flow channels. For example, housing 1708 may form a first channel configured to allow gas to flow (e.g., from a gas stick assembly, gas flow assembly, etc.) in a first direction (e.g., vertically upward in FIG. 17B ). Housing 1708 may further form a second channel configured to allow gas to flow in a second direction (e.g., vertically downward in FIG. 17B ). The second direction may be opposite to the first direction. For example, the first channel may allow gas to flow upward, while the second channel may allow gas to flow downward (e.g., as shown in FIG. 17A-C ). The first channel may include a first opening 1781 in the bottom surface of housing 1708 and a second opening 1782 in the top surface of housing 1708. Gas may be received from the gas stick assembly via first opening 1781. Gas may be supplied to auxiliary components (e.g., valves, regulators, filters, regulators, mass flow controllers, etc.) mounted on top of sensor assembly 1700A via second opening 1782. In some embodiments, the second channel may include a third opening 1783 in the top surface of housing 1708 to receive gas from auxiliary components. The second channel may include a fourth opening in the bottom surface of housing 1708 to supply gas to the gas stick assembly. The second channel may form a return gas flow path to provide gas to downstream components of the gas stick assembly. In some embodiments, housing 1708 receives gas from upstream components of the gas stick assembly. Similarly, in some embodiments, housing 1708 is used to supply gas to downstream components of the gas stick assembly.

[0256] In some embodiments, first opening 1781, second opening 1782, third opening 1783, and / or fourth opening 1784 include areas configured to receive sealing components. For example, second opening 1782 may include a recessed portion to receive an O-ring. The O-ring may be made of a material suitable for sealing the interface between housing 1708 and auxiliary components. In some embodiments, second opening 1782 and third opening 1783 are configured to receive an end plug (e.g., end plug 1786 in Figures 17E and 17F) to direct gas from the first channel to the second channel. In some embodiments, the sealing portion of first opening 1781 seals the interface between housing 1708 and a base portion (e.g., a body) of the gas stick assembly.

[0257] In some embodiments, filter / layer element 1722 is positioned within a channel of housing 1708. In some embodiments, filter / layer element 1722 is a mesh. Filter / layer element 1722 may be bonded to the inner surface of the first channel of housing 1708. In some embodiments, filter / layer element 1722 may promote laminar airflow through the first channel and / or the second channel of housing 1708. As gas flows through filter / layer element 1722, the airflow may be straightened (e.g., by the openings of filter / layer element 1722). The straightened airflow may flow in a laminar manner.

[0258] In some embodiments, housing 1708 forms a recess in a side surface thereof, into which substrate 1702 (e.g., substrates 402, 502, 602, 702, 802, 902, or 1002) is mounted. Substrate 1702 may include electrical contact pads 1714 and electrical connections to one or more electrodes of sensor device 300, which may be bonded to substrate 1702 using any bonding technique described herein. In some embodiments, sensor device 300 may be positioned and / or oriented relative to substrate 1702 using any one or more alignment features and / or techniques described herein. In some embodiments, sensor device 300 is positioned in the first channel. In some embodiments, sensor device 300 is positioned in the second channel. Placing sensor device 300 in the second channel may help establish laminar airflow through housing 1708. In some embodiments, sensor assembly 1700A includes two substrates 1702 and two sensor devices 300 (each attached to one of the two substrates), each disposed in one of the first or second channels. In some embodiments, substrate 1702 is coupled to the housing via flange / adapter 1300. In some embodiments, flange / adapter 1300 can be made of a stainless steel alloy or Kovar. In some embodiments, substrate 1702 is bonded to flange / adapter 1300 by welding or brazing, as described above. In some embodiments, flange / adapter 1300 is bonded to housing 1708 by welding or brazing, as described above. In some embodiments, substrate 1702 and housing 1708 are coupled to form a hermetic seal. In some embodiments, support ring 1703 (e.g., support ring 1500) is brazed or welded to adapter / flange 1300 to reduce mechanical and / or thermal stress at one or more joints (e.g., welded joints, brazed joints, etc.) between substrate 1702, adapter / flange 1300, and / or housing 1708. In some embodiments, each of adapter / flange 1300 and support ring 1703 may include a through-hole to receive substrate 1702 (e.g., as shown in FIG. 17C ). Similarly, housing 1708 may include a hole to receive substrate 1702 (e.g., as shown in FIG. 17C ). In some embodiments, sensor assembly 1700A includes a second sensor disposed within the housing. The second sensor may be attached to the second substrate. The second sensor may be selected from the group consisting of a temperature sensor, a flow sensor, or a pressure sensor. The second sensor may be configured to sense a condition of gas flowing through either the first channel or the second channel. In some embodiments, a pressure sensor configured to sense gas pressure is disposed in a first channel, and a flow sensor (eg, sensor device 300 ) is disposed in a second channel.

[0259] Figure 17E illustrates a perspective view of sensor assembly 1700B according to an embodiment of the present disclosure. Figure 17F illustrates a front view of section GG in Figure 17F. In some embodiments, sensor assembly 1700B includes features similar to those of sensor 1700A described above (e.g., housing 1708, substrate 1702, first opening 1781, sensor device 300, filter / layered element 1722, etc.). In some embodiments, sensor assembly 1700B includes end plugs 1786. End plugs 1786 can be bonded to the top surface of housing 1708 (e.g., by welding, brazing, soldering, etc.). In some embodiments, end plugs 1786 are bonded to second opening 1782 and third opening 1783 (e.g., the second opening and third opening in Figures 17A and 17D). In some embodiments, end plugs 1786 block second opening 1782 and third opening 1783. Housing 1708 and / or end plug 1786 may include a channel (e.g., a third channel) connecting the first channel and the second channel to direct gas flow from the first channel to the second channel. In some embodiments, housing 1708 of sensor assembly 1700B is configured to receive gas from the gas stick assembly via first opening 1781 and direct the gas back to the gas stick assembly via fourth opening 1784. In some embodiments, sensor assembly 1700B includes a second sensor disposed within the housing. The second sensor may be selected from the group consisting of a temperature sensor, a flow sensor, or a pressure sensor. The second sensor may be configured to sense a condition of gas flowing through either the first channel or the second channel.

[0260] Figure 17G illustrates a cross-sectional view of sensor assembly 1700C, according to an embodiment of the present disclosure. In some embodiments, sensor assembly 1700C includes a pressure sensor 1792 disposed within housing 1708. Pressure sensor 1792 can sense the pressure of gas flowing through one or more channels of housing 1708. In some embodiments, sensor assembly 1700C includes a sensor device 300 coupled to substrate 1702. Sensor device 300 can be disposed in a gas return channel of housing 1708. In some embodiments, the placement of sensor device 300 can facilitate laminar gas flow through housing 1708.

[0261] Figure 17H ​​illustrates a schematic diagram of a sensor assembly (e.g., sensor assembly 1700A or 1700B) coupled to a gas stick assembly, according to an embodiment of the present disclosure. Multiple gas stick assemblies can receive gas from multiple gas supplies. For example, a processing tool can include a different gas stick assembly for each gas delivered to a process chamber. As shown, gas flows through the gas stick assemblies from left to right. In some embodiments, gas stick assembly 1750 includes a mixing valve 1751, which can be the first component of gas stick assembly 1750. The mixing valve can include a manual valve or an automatically actuated valve (e.g., a pneumatic valve, an electric valve, etc.). Mixing valve 1751 can receive gas from a gas source (not shown). Mixing valve 1751 can direct the gas to purge valve 1752 via one or more channels. Purge valve 1752 can be configured to purge gas stick assembly 1750. In some embodiments, gas stick assembly 1750 includes a regulator 1753. Regulator 1753 receives gas from purge valve 1752. Regulator 1753 can regulate the flow of gas through gas stick assembly 1750. In some embodiments, sensor assemblies 1700A and 1700B (e.g., sensor assembly 1700A or 1700B) can be coupled downstream of regulator 1753. Sensor assemblies 1700A and 1700B can be gas flow sensors for gas stick assembly 1750. In some embodiments, filter 1754 is coupled to sensor assemblies 1700A and 1700B and receives gas flow from sensor assemblies 1700A and 1700B (e.g., via the first channel described in Figures 17A-C). Filter 1754 can provide gas flow back to sensor assemblies 1700A and 1700B (e.g., to third opening 1783 in Figures 17A-17D). In some embodiments, upstream valve 1755 can receive gas from sensor assemblies 1700A and 1700B and direct the gas flow to mass flow controller 206. In some embodiments, sensor assemblies 1700A, 1700B function as mass flow controllers, and no additional mass flow controller is included in gas stick assembly 1750. Mass flow controller 1756 and / or sensor assemblies 1700A, 1700B can control the flow of gas through gas stick assembly 1750. In some embodiments, downstream valve 1757 receives gas from a mass flow controller or other upstream component. Downstream valve 1757 can direct the gas to a gas destination (e.g., a processing chamber; not shown).

[0262] While sensor assemblies 1700A, 1700B are illustrated and described as being positioned below filter 1754 along the airflow path, those skilled in the art will recognize that sensor assemblies 1700A, 1700B may alternatively be positioned anywhere along the airflow path of air stick assembly 1750. For example, sensor assemblies 1700A, 1700B may be positioned upstream and / or downstream of any of the aforementioned components of the air stick assembly. As another example, sensor assemblies 1700A, 1700B may be positioned below any of the aforementioned devices. Sensor assemblies 1700A, 1700B may receive airflow from upstream components of air stick assembly 1750 and direct the airflow toward downstream components of air stick assembly 1750.

[0263] FIG17I illustrates a perspective view of a sensor assembly (e.g., sensor assembly 1700A) coupled to a gas stick assembly 1750, according to an embodiment of the present disclosure. Multiple gas stick assemblies can receive gases from multiple gas supplies. For example, a processing tool can include a different gas stick assembly for each gas delivered to a process chamber. As shown, gases flow through the gas stick assemblies from left to right.

[0264] In some embodiments, gas stick assembly 1750 includes a base 1759. Gas stick assembly 1750 can receive gas (e.g., from a gas source) via gas coupler 1758. In some embodiments, gas stick assembly 1750 includes a mixing valve 1751, a purge valve 1752, a regulator 1753, sensor assembly 1700A, a filter 1754, an upstream valve 1755, a mass flow controller 1756, and / or a downstream valve 1757. In some embodiments, each of mixing valve 1751, purge valve 1752, regulator 1753, sensor assembly 1700A, filter 1754, upstream valve 1755, mass flow controller 1756, and / or downstream valve 1757 is coupled to gas stick assembly base 1759. In some embodiments, filter 1754 can be coupled to a top surface of sensor assembly 1700A. As will be appreciated by those skilled in the art, the sensor assembly 1700A can be coupled between the base 1759 and any of the mixing valve 1751, the purge valve 1752, the regulator 1753, the sensor assembly 1700A, the filter 1754, the upstream valve 1755, the mass flow controller 1756, and / or the downstream valve 1757. Similarly, in some embodiments, any of the mixing valve 1751, the purge valve 1752, the regulator 1753, the sensor assembly 1700A, the filter 1754, the upstream valve 1755, the mass flow controller 1756, and / or the downstream valve 1757 can be coupled to the top surface of the sensor assembly 1700A. In some embodiments, the sensor assembly 1700A is coupled between the base 1759 and a pressure sensor (not shown).

[0265] FIG18 illustrates a diagrammatic representation of a machine in the exemplary form of a computer system 1800, within which a set of instructions (e.g., for causing the machine to perform any one or more of the methodologies discussed herein) may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a LAN, WAN, intranet, extranet, or the Internet. The machine may operate as a server or client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), tablet PC, PDA, cellular phone, web appliance, server, network router, switch, or bridge, or any machine capable of executing (sequentially or otherwise) a set of instructions that specify actions to be taken by the machine. Furthermore, while a single machine is illustrated, the term "machine" should be construed to include any collection of machines that individually or collectively execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Some or all components of computer system 1800 may utilize or account for any electronic components described herein (eg, processing device 230 or any electronic components utilized in conjunction with operation of chamber 101 or flow modulator 210).

[0266] The exemplary computer system 1800 includes a processing device (processor) 1802, a main memory 1804 (e.g., ROM, flash memory, dynamic random access memory (DRAM) such as synchronous dynamic random access memory (SDRAM) or Rambus DRAM (RDRAM)), etc.), a static memory 1806 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 1820, which communicate with each other via a bus 1810.

[0267] Processor 1802 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, or the like. More specifically, processor 1802 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or a processor implementing another instruction set, or a combination of instruction sets. Processor 1802 may also be one or more special-purpose processing devices, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), a network processor, or the like. Processor 1802 is configured to execute instructions 1840 to perform the operations and steps discussed herein.

[0268] The computer system 1800 may further include a network interface device 1808. The computer system 1800 may also include a video display unit 1812 (e.g., a liquid crystal display (LCD), a cathode ray tube (CRT), or a touch screen), an alphanumeric input device 1814 (e.g., a keyboard), a cursor control device 1816 (e.g., a mouse), and a signal generating device 1822 (e.g., a speaker).

[0269] Power supply device 1818 can monitor the power level of a battery used to power computer system 1800 or one or more of its components. Power supply device 1818 can provide one or more interfaces that provide an indication of the power level, the time window remaining before computer system 1800 or one or more of its components shuts down, power consumption rate, an indicator of whether the computer system is utilizing external power or battery power, and other power-related information. In some embodiments, indications related to power supply device 1818 can be accessed remotely (e.g., by a remote backup management module via a network connection). In some embodiments, the battery utilized by power supply device 1818 can be a local or remote uninterruptible power supply (UPS) in computer system 1800. In such embodiments, power supply device 1818 can provide information regarding the power level of the UPS.

[0270] Data storage device 1820 may include a computer-readable storage medium 1824 (e.g., a non-transitory computer-readable storage medium) storing one or more sets of instructions 1840 (e.g., software) embodying any one or more of the methodologies or functions described herein. These instructions 1840 may also reside, completely or at least partially, within main memory 1804 and / or processor 1802 during execution of these instructions by computer system 1800, with main memory 1804 and processor 1802 also constituting computer-readable storage media. Instructions 1840 may further be transmitted or received over network 1830 via network interface device 1808. While computer-readable storage medium 1824 is shown as a single medium in one exemplary embodiment, it should be understood that computer-readable storage medium 1824 may also include a single medium or multiple media (e.g., a centralized or distributed database and / or associated cache and server) storing the one or more sets of instructions 1840.

[0271] In the foregoing description, many details are set forth. However, those of ordinary skill in the art having the benefit of this disclosure will appreciate that the disclosure may be practiced without these specific details. Although specific embodiments are described herein, it should be understood that they are presented by way of example and not limitation. The breadth and scope of this application should not be limited by any of the embodiments described herein, but should be defined solely in accordance with the claims and their equivalents set forth below and thereafter. Indeed, various other embodiments of the disclosure and modifications thereto, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Therefore, such other embodiments and modifications are intended to fall within the scope of this disclosure.

[0272] Reference is made to the accompanying drawings, which form a part of this description, in which specific embodiments are shown by way of illustration. While the disclosed embodiments are described in sufficient detail to enable those skilled in the art to practice them, it should be understood that these embodiments are not limiting, and that other embodiments may be used and changes may be made to the disclosed embodiments without departing from the spirit and scope of the disclosed embodiments. For example, the blocks of the methods shown and described herein need not be performed in the order shown in some other embodiments. Furthermore, in some other embodiments, the disclosed methods may include more or fewer blocks than described. As another example, some blocks described herein as separate blocks may be combined in some other embodiments. Conversely, what may be described herein as a single block may be implemented in multiple blocks in some other embodiments. Furthermore, unless otherwise indicated, the conjunction "or" is intended to be inclusive herein where appropriate; that is, the statement "A, B, or C" is intended to include the possibilities of "A," "B," "C," "A and B," "B and C," "A and C," and "A, B, and C."

[0273] The words "example" or "exemplary" are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as an "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, the use of the words "example" or "exemplary" is intended to present concepts in a concrete manner. When the terms "about" or "approximately" are used herein, these terms are intended to mean that the nominal value presented is accurate within ±10%.

[0274] Furthermore, the articles "a" and "an" as used herein and in the appended claims should generally be interpreted as meaning "one or more," unless otherwise specified or clear from context to refer to a singular form. References throughout this specification to "one embodiment," "some embodiments," or "certain embodiments" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "one embodiment," "some embodiments," or "certain embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment.

[0275] Portions of the detailed description may be presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. Here, an algorithm is generally considered to be a self-consistent sequence of steps leading to a desired result. These steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0276] It should be remembered, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless otherwise specifically stated, it will be understood from the following discussion that throughout the description, discussions utilizing terms such as "receive," "acquire," "transmit," "calculate," "generate," "process," "reprocess," "add," "subtract," "multiply," "divide," "optimize," "calibrate," "detect," "execute," "analyze," "determine," "enable," "identify," "modify," "convert," "apply," "result in," "store," "compare," or similar terms refer to the actions and processes of a computer system or similar electronic computing device that manipulate and transform data represented as physical (e.g., electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system's registers or memories or other such information storage, transmission, or display devices.

[0277] Furthermore, while the present disclosure has been described herein in the context of specific embodiments, in a specific environment, for a specific purpose, one of ordinary skill in the art will recognize that its usefulness is not limited thereto, and that the present disclosure can be advantageously implemented in any number of environments and for any number of purposes. Accordingly, the claims set forth below should be interpreted in light of the full breadth and spirit of the present disclosure as described herein, along with the full scope of equivalents to which such claims are entitled.

[0278] 100: System 101: Processing chamber 102: Chamber body 106: Internal volume 108: Sidewall 110: bottom 112: Supply Pipeline 116: Outer lining 126: Exhaust port 128: Pump system 130:Showerhead 132: Gas delivery hole 144:Substrate 148: substrate support assembly 150:Electrostatic chuck 152: Base 160: Gas source 170:Sensor assembly 200: Flow control device 210: Flow Modulator 220:Sensor component 222:Sensor equipment 230: Processing Equipment 240: airflow channel 242: Flow Path 300:Sensor equipment 302: Support structure 304: Interface area 306: sensor area 308: Sensing element 312: Cavity 314: Electrical contacts 400:Sensor component 402:Substrate 404: Shell 414: Electrical contact pad 416: Conductor needle 420: coating 460: Gas-facing surface 470: relative surface 490: Seal 492:T-shaped connector 500:Sensor component 502:Substrate 504: Shell 514: electrical contact pad 560: Gas-facing surface 570: relative surface 580:O-ring 590: Seal 592:T-shaped connector 600:Sensor component 602:Substrate 604: Shell 614: Electrical contact pad 616: Conductor needle 660: Gas-facing surface 670: Relative surface 690: Seal 700:Sensor component 702:Substrate 704: Shell 714: Electrical contact pad 760: Gas-facing surface 770: relative surface 800:Sensor component 802:Substrate 814: Electrical contact pad 900:Sensor component 902:Substrate 904: Shell 914: Electrical contact pad 960: Gas-facing surface 970: relative surface 1000:Sensor component 1002:Substrate 1004: Shell 1014: Electrical contact pad 1060: Gas-facing surface 1070: Relative surface 1100: Method 1110: Block 1120: Block 1130: Block 1140: Block 1200: Method 1202:Substrate 1203:Copper bonding wire 1204: Shell 1210: Block 1214: Electrical contact pad 1220: Block 1230: Block 1240: Block 1250: Block 1260: Block 1278:Screw 1280:O-ring 1300:Adapter / Flange 1302:Substrate 1303: concave part 1399: flange 1400: System 1401:Sensor equipment 1402:Substrate 1403:Sensor equipment 1404:Substrate 1410: protrusion 1412: Alignment Features 1414: Alignment Features 1416: Box 1417: Alignment Features 1418: Alignment Features 1420: concavity / notch 1422: Alignment mark 1450: Airflow 1500: Support Ring 1502:Substrate 1503:Sensor equipment 1504: Vacuum port 1512: Fixture 1514: Electrical contact pad 1515: Electrode 1516:Through hole 1517:Metal Adhesion Layer 1518:Solder 1519: foil 1521:Metal wire 1522: Fusion Joint 1524: Radiation 1526:Lamination layer 1602: Block 1604: Block 1606: Block 1608: Block 1612: Block 1614: Cube 1616: Block 1618: Block 1620: Block 1622: Block 1632: Block 1634: Block 1636: Block 1638: Block 1640: Block 1642: Block 1652: Block 1654: Block 1656: Block 1658: Block 1662: Cube 1664: Cube 1666: Block 1668: Block 1670: Block 1672: Cube 1674: Cube 1702:Substrate 1703: Support Ring 1708: Shell 1714:Electrical contact pad 1722:Filter / Layered Element 1750: Gas rod assembly 1751:Mixing valve 1752:Purge valve 1753: Regulator 1754:Filter 1755:Upstream valve 1756:Mass Flow Controller 1757: Downstream valve 1758:Gas Coupler 1759: Base 1781: Opening 1782: Opening 1783: Opening 1784: Opening 1786: End plug 1792:Pressure Sensor 1800: Computer systems 1802: Processing device / processor 1804: Main memory 1806: Static Memory 1808: Network Interface Device 1810: Bus 1812: Video display unit 1814: Alphanumeric input device 1816: Cursor Control Device 1818: Power supply equipment 1820: Data storage device 1822:Signal Generating Equipment 1824: Computer-readable storage media 1830: Internet 1840: Instructions 1002I: Internal area 1002M: Middle area 1002M1: Surface 1002M2: Surface 1002O: External area 1004C: Tubular gas channel 1004M: Area 1080A: Slot 1201A:Sensor assembly 1201B:Sensor assembly 1300A: Seals 1300B: Seals 1300C: Seals 1300D: Seals 1300S1: First side 1300S2: Second side 1501A: System 1501B: System 1501C: System 1501D: System 1501E: System 1501F: System 1501G:System 1600A: Method 1600B: Method 1600C: Method 1600D: Method 1600E: Method 1600F: Method 1700A:Sensor Assembly 1700B:Sensor Assembly 1700C:Sensor assembly 402I: Internal Area 402M: Middle area 402O: External Area 420A: Seals / Adhesives 420B: Seals / Adhesives 420C: Seals / Adhesives 420D: Seals / Adhesives 422A: Layer 422B: Layer 422C: Layer 422D: Layer 480A: Slot 480B: Slot 480C: Slot 502A: Layer 502B: Layer 502I: Internal area 502M: Middle area 502O: External area 520A: Seals / Adhesives 520B: Seals / Adhesives 580A: Slot 580B: Slot 580C: Slot 602I: Internal area 602M: Middle area 602O: External Area 616H: Conductor pinhole 620A: Seals / Adhesives 620B: Seals / Adhesives 620D: Seals / Adhesives 620E: Seals 680A: Slot 680B: Slot 680C: Slot 702A: Layer 702B: Layer 702I: Internal area 702M: Middle area 702O: External area 720A: Seals / Adhesives 720B: Seals / Adhesives 765A: First end 765B: Second end 780A: Slot 780B: Slot 802A: First end 802B: Second end 802I: Internal area 802M1: Middle area 802M2: Middle area 802O1: External Area 802O2: External area 820A: Seals 820B: Seals 820C: Seals 902I: Internal Area 902M: Middle area 902M1: Surface 902M2: Surface 902O: External area 980A: Slot

[0279] Domestic storage information (please note the order of storage institution, date, and number) none

[0280] Overseas deposit information (please note the order of deposit country, institution, date, and number) none

Claims

1. A sensor assembly, comprising: A substrate includes an outer region, an inner region, and an intermediate region positioned between the outer region and the inner region, the substrate further including one or more electrical contact pads located at least on the inner region; a housing coupled to the substrate via a flange at the intermediate region or the outer region, the flange providing an hermetically sealed connection between the housing and the substrate, wherein the one or more electrical contact pads extend beyond the housing located on an outermost surface of the substrate at the inner region. And a sensor die coupled to the substrate in the inner region via the electrical contact pads, wherein the sensor die is aligned with the substrate in at least one of a first plane or a second plane via one or more alignment features, wherein the one or more alignment features are formed on at least one outermost surface of the substrate in the inner region.

2. The sensor assembly of claim 1, wherein the one or more alignment features align the sensor die relative to the substrate in the first plane, wherein the first plane is perpendicular to an interface between the sensor die and the substrate, wherein the one or more alignment features include a first set of protrusions projecting from the sensor die, wherein the substrate forms a first set of alignment holes, each of the first set of alignment holes being configured to receive a corresponding protrusion of the first set of protrusions, and wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the substrate in the first plane in response to receiving the first set of protrusions by the first set of alignment holes.

3. The sensor assembly of claim 1, wherein the one or more alignment features align the sensor die relative to the substrate in the first plane, wherein the first plane is perpendicular to an interface between the sensor die and the substrate, wherein the one or more alignment features include a first set of protrusions projecting from the substrate, wherein the sensor die forms a first set of alignment holes, each of the first set of alignment holes being configured to receive a corresponding protrusion of the first set of protrusions, and wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the substrate in the first plane in response to receiving the first set of protrusions by the first set of alignment holes.

4. The sensor assembly as claimed in claim 1, wherein the one or more alignment features cause the sensor die to be positioned at a target location on the substrate such that the sensor die is centered in a gas channel during use of the sensor assembly.

5. The sensor assembly of claim 1, wherein the one or more alignment features align the sensor die relative to the substrate in the second plane, wherein the one or more alignment features include a plurality of solder contacts, wherein each of the plurality of solder contacts has a controlled thickness substantially the same as the controlled thickness of the remaining solder contacts, and wherein the second plane is parallel to an interface between the sensor die and the substrate.

6. The sensor assembly as claimed in claim 5, wherein the plurality of solder contacts comprises: A first solder contact is used to couple a first electrode of the bare die of the sensor to a first electrical contact pad in one or more electrical contact pads; And a second solder contact, which couples a second electrode of the sensor die to a second electrical contact pad in one or more electrical contact pads.

7. The sensor assembly as claimed in claim 6, wherein: The first electrode is substantially aligned with a first via formed in the substrate, and the first solder contact includes a first amount of solder that at least partially fills the first via to bond the sensor die to the substrate. The second electrode is substantially aligned with a second via formed in the substrate, and the second solder contact includes the first amount of solder that at least partially fills the second via to bond the sensor die to the substrate.

8. The sensor assembly as claimed in claim 7, further comprising: A laminate is disposed on the first amount of solder and on at least a portion of a surface of the substrate adjacent to the first through hole and the second through hole.

9. The sensor assembly of claim 1, wherein a first electrical contact pad of the one or more electrical contact pads is fused to a first electrode of the sensor die to form the one or more alignment features, and wherein one or more of the sensor die or the substrate comprises a material substantially transparent to a predetermined wavelength of radiation.

10. The sensor assembly as claimed in claim 1, further comprising a conformal coating disposed on one or more outer surfaces of the sensor assembly.

11. The sensor assembly of claim 1, wherein the one or more alignment features include a first set of alignment features and a second set of alignment features, the first set of alignment features aligning the sensor die relative to the substrate in a first plane, and the second set of alignment features aligning the sensor die relative to the substrate in a second plane, wherein the second plane is perpendicular to the first plane.

12. A gas flow sensor configured to be coupled to a gas flow tube via a flange, the gas flow sensor comprising: A dielectric substrate includes an outer region, an inner region, and an intermediate region positioned between the outer region and the inner region. The dielectric substrate includes one or more electrical contact pads formed between layers of the dielectric substrate, wherein the one or more electrical contact pads extend at least partially through the dielectric substrate from the outer region to the inner region. A housing is coupled to the dielectric substrate at the intermediate region via a flange, the flange forming a hermetically sealed connection between the housing and the dielectric substrate. The one or more electrical contact pads extend at the inner region beyond the housing located on an outermost surface of the dielectric substrate. And a sensor die coupled to the dielectric substrate in the inner region via the electrical contact pads, wherein the sensor die is aligned with the dielectric substrate in at least one of a first plane or a second plane via one or more alignment features, wherein the one or more alignment features are formed in the inner region on at least one outermost surface of the dielectric substrate.

13. The gas flow sensor of claim 12, wherein the one or more alignment features align the sensor die relative to the dielectric substrate in the first plane, wherein the first plane is perpendicular to an interface between the sensor die and the dielectric substrate, wherein the one or more alignment features include a first set of protrusions projecting from the sensor die, wherein the dielectric substrate forms a first set of alignment holes, each of the first set of alignment holes being configured to receive a corresponding protrusion of the first set of protrusions, and wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the dielectric substrate in the first plane in response to receiving the first set of protrusions by the first set of alignment holes.

14. The gas flow sensor of claim 12, wherein the one or more alignment features cause the sensor die to be positioned at a target location on the dielectric substrate such that the sensor die is centered in a gas channel during use of the gas flow sensor.

15. The gas flow sensor of claim 12, wherein the one or more alignment features align the sensor die relative to the dielectric substrate in the second plane, wherein the one or more alignment features include a plurality of solder contacts, wherein each of the plurality of solder contacts has a controlled thickness substantially the same as the controlled thickness of the remaining solder contacts, and wherein the second plane is parallel to an interface between the sensor die and the dielectric substrate.

16. A method of manufacturing a sensor assembly, the method comprising the steps of: providing a substrate including an outer region, an inner region, and an intermediate region positioned between the outer region and the inner region, the substrate further including one or more electrical contact pads at least located on the inner region; aligning a sensor die in the inner region with the substrate within at least one of a first plane or a second plane via one or more alignment features, wherein the one or more alignment features are formed on at least one outermost surface of the substrate in the inner region; coupling the sensor die to the substrate in the inner region; and coupling the substrate to a housing via a flange in the intermediate region or the outer region, the flange providing a hermetically sealed connection between the housing and the substrate, wherein the one or more electrical contact pads extend beyond the housing located on an outermost surface of the substrate in the inner region.

17. The method of claim 16, wherein the step of aligning the sensor die with the substrate via the one or more alignment features includes the following steps: inserting a first set of protrusions protruding from the sensor die into a first set of alignment holes formed by the substrate, wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the substrate in the first plane in response to receiving the first set of protrusions in the first set of alignment holes.

18. The method of claim 16, wherein the step of aligning the sensor die with the substrate via the one or more alignment features comprises the following steps: placing a first solder bump on a first electrical contact pad of the one or more electrical contact pads; placing a second solder bump on a second electrical contact pad of the one or more electrical contact pads; flattening a top surface of each of the first solder bump and the second solder bump by a pressing process to form each of the first solder bump and the second solder bump into a substantially cylindrical shape; and placing a first electrode of the sensor die on the flattened first solder bump and a second electrode of the sensor die on the flattened second solder bump to bond the sensor die to the substrate via the first solder bump and the second solder bump.

19. The method of claim 16, further comprising the steps of: placing the sensor die in a jig, wherein a first electrode and a second electrode of the sensor die are exposed in response to the sensor die being placed in the jig; aligning a first via formed by the substrate and a second via formed by the substrate with the first electrode and the second electrode, respectively; placing the substrate adjacent to the sensor die; and filling each of the first via and the second via with a first amount of solder to at least partially fill the first via and the second via to bond the sensor die to the substrate.

20. The method of claim 16, further comprising the steps of: directing radiation from a fusion splicer through at least one of the sensor die or the substrate to a first metal contact region of a first electrode of the sensor die and a first electrical contact pad of one or more electrical contact pads to fuse the first electrode to the first electrical contact pad of the substrate, wherein the first metal contact region functions as a first alignment feature of one or more alignment features, and wherein at least one of the sensor die or the substrate includes a material substantially transparent to a wavelength of the radiation; and directing radiation from the fusion splicer through at least one of the sensor die or the substrate to a second metal contact region of a second electrode of the sensor die and a second electrical contact pad of one or more electrical contact pads to fuse the second electrode to the second electrical contact pad of the substrate, wherein the second electrical contact pad and the second electrode function as a second alignment feature of one or more alignment features.

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