Micro electro mechanical device for use in flow control devices

Abstract

Embodiments of sensor devices, systems incorporating the sensor devices, and methods of manufacturing the sensor devices are disclosed herein. In one embodiment, a sensor device includes a standalone sensing element, such as a microelectromechanical system (MEMS) device. The sensor device further includes a metal strap to facilitate mounting of the MEMS device to a mounting plate. The sensor device further includes a conformal coating on at least a portion of a sensor region of the sensor device.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to methods and apparatus for monitoring and controlling the flow rate of gases. Background Technology

[0002] Controlling gas flow rates is a common challenge in manufacturing systems. In some manufacturing systems, process gases (i.e., gases used during semiconductor manufacturing processes) and / or cleaning gases (i.e., gases used in cleaning equipment and / or chambers used in manufacturing electronic devices) may have precise delivery targets including high-quality flow rates (i.e., 500 standard liters per minute or more) and the ability to precisely control low flow rates (i.e., 10 standard liters per minute or less). Known manufacturing systems often use one or more mass flow controllers (MFCs) to measure and control the mass flow rate of process gases.

[0003] Each type of MFC (e.g., thermal MFC, pressure-based MFC, decay rate-based MFC, etc.) may impose one or more limitations depending on the application in which the MFC is used. For example, thermal MFCs utilize thermal sensors to measure flow and control needle valves to regulate flow direction in the downstream processing chamber. The feedback from such thermal sensors is very slow, resulting in a slow response rate for the MFC (on the order of 100 milliseconds or longer). This makes thermal MFCs impractical for manufacturing applications requiring precise gas control and timing. Summary of the Invention

[0004] Some embodiments of this disclosure relate to sensor devices, systems integrating sensor devices, and methods for adapting sensor devices for use in flow control equipment. In one aspect of this disclosure, a sensor device includes an elongated support structure, electrodes, and a freestanding sensing element. The elongated support structure includes an interface region, a sensor region, and a coupling region located between the interface region and the sensor region. Electrodes are disposed on the interface region, and a freestanding sensor element is suspended at the sensor region and electrically coupled to the electrodes. In some embodiments, the sensor device includes a metal strip surrounding the coupling region. In some embodiments, the sensor device includes a non-conductive conformal coating on at least a portion of the sensor region. In some embodiments, the sensor device includes a micro-electromechanical system (MEMS) device.

[0005] In another aspect of this disclosure, a flow control device includes a gas flow channel defining a gas flow path, a flow control valve configured to regulate gas flow in the gas flow channel, a sensor device including a stand-alone sensing element, and a processing device. In some embodiments, the stand-alone sensing element is disposed within the gas flow path. In some embodiments, the processing device is operatively coupled to the flow control valve and the sensor device, and is configured to control the flow control valve based on signals received from the flow sensor device. In some embodiments, the sensor device includes a microelectromechanical system (MEMS) device.

[0006] In another aspect of this disclosure, a method of adapting a sensor device for flow in a gas flow channel includes providing the sensor device, depositing a conformal coating on the sensor device to at least partially coat a sensor region of the sensor device, and depositing a metal strip on the sensor device to surround a coupling region of the sensor device. In some embodiments, the sensor device includes an elongated support structure comprising an interface region, a sensor region, and a coupling region located between the interface region and the sensor region. Attached Figure Description

[0007] The accompanying drawings, illustrated by way of example but not limitation, show the same reference numerals indicating the same elements. It should be noted that different references to “an” or “one” embodiments in this disclosure do not necessarily refer to the same embodiments, and such references imply at least one.

[0008] Figure 1 An exemplary system including a processing chamber, a gas source, and a flow control device according to an embodiment of the present disclosure is shown.

[0009] Figure 2 An exemplary flow control device according to an embodiment of the present disclosure is shown.

[0010] Figure 3A A top view of an exemplary MEMS device according to an embodiment of the present disclosure is shown.

[0011] Figure 3B A side view of an exemplary MEMS device according to an embodiment of the present disclosure is shown.

[0012] Figure 3C A stand-alone sensing element of an exemplary MEMS device according to an embodiment of this disclosure is shown.

[0013] Figure 4A A top view of an exemplary MEMS device suitable for use in a flow control device, according to an embodiment of the present disclosure, is shown.

[0014] Figure 4B A side view of an exemplary MEMS device suitable for use in a flow control device, according to an embodiment of the present disclosure, is shown.

[0015] Figure 4C A cross-sectional view of a conformal coating formed on the surface of an exemplary MEMS device according to an embodiment of the present disclosure is shown.

[0016] Figure 5A A top view of an exemplary mounting plate according to an embodiment of this disclosure is shown.

[0017] Figure 5B A side cross-sectional view of an exemplary mounting plate according to an embodiment of the present disclosure is shown.

[0018] Figure 5C An exemplary MEMS device prior to insertion through a slot in an exemplary mounting plate is shown, according to an embodiment of the present disclosure.

[0019] Figure 5D An exemplary MEMS device is shown inserted into a slot of an exemplary mounting plate according to an embodiment of the present disclosure.

[0020] Figure 5E An exemplary MEMS device is shown, which is mounted in a slot within an exemplary mounting plate via a metal seal according to an embodiment of the present disclosure.

[0021] Figure 5F An exemplary MEMS device coupled to a gas flow channel via an exemplary mounting plate is shown according to an embodiment of the present disclosure.

[0022] Figure 6 A method for adapting a sensor device for use in a flow control apparatus according to an embodiment of the present disclosure is shown.

[0023] Figure 7 This is a block diagram illustrating a computer system used according to an embodiment of the present disclosure. Detailed Implementation

[0024] The embodiments described herein relate to sensor devices suitable for use in mass flow control equipment, systems incorporating such sensor devices, and methods for adapting such sensor devices for this purpose. In some embodiments, the sensor device includes a MEMS device with a freestanding sensor element that is directly disposed in the flow path of a gas flow channel. The MEMS device has a conformal coating formed thereon to protect it from corrosive gases and has a metal strip to allow for the formation of a metal seal between the MEMS device and a mounting plate or other device or structure to which the MEMS device is mounted.

[0025] Typically, precise control of the flow rate of process gases used in manufacturing processes is advantageous for better process control and to allow for the satisfaction of precise process constraints. The low transient response rate of current MFCs, typically on the order of 100 microseconds or larger, is unsuitable for applications requiring precise control of gas dosage, such as the delivery of small amounts of gas or the continuous delivery of pulses of one or more gases with pulse widths on the order of 100 milliseconds or smaller.

[0026] Embodiments of this disclosure advantageously overcome the limitations of current MFCs by utilizing MEMS devices directly within the gas flow path to provide fast (i.e., transient response of less than about 1 millisecond) and accurate flow feedback. Processing devices operatively coupled to MEMS devices (such as EtherCAT® plug-in modules (EPMs)) can control MFCs or independently actuated valves more rapidly based on fast flow feedback compared to conventional MFCs. While various embodiments may utilize MEMS devices as the sole source of feedback, flow feedback from MFC devices can also be advantageously used in conjunction with MEMS feedback, for example, for calibration or verification purposes (e.g., to ensure consistency between measured signals).

[0027] In addition to flow feedback, MEMS devices can be advantageously used to provide rapid and accurate temperature measurement at any location on the gas supply line, including at the source, near the valve, near the inlet (i.e., delivery point) leading to the processing chamber, or inside the processing chamber. The temperature measurement can be monitored in real time by the processing device, which can then send power output commands to the heating units at different locations on the gas supply line.

[0028] Certain implementations advantageously adapt MEMS devices to be directly inserted into gas flow paths while protecting them from the corrosive effects of the gas. For example, in some implementations, a protective, non-conductive conformal coating is deposited onto the surface of the MEMS device exposed to the gas during operation. For instance, atomic layer deposition (ALD) or ion-assisted deposition (IAD) techniques can be used to form conformal coatings on at least a portion of the MEMS device. For example, ALD technology can form conformal coatings of substantially uniform thickness and zero porosity (i.e., no porosity) on all exposed surfaces of the component to be coated, including features with complex geometries and / or high aspect ratios. The coating can be plasma-resistant to reduce plasma interactions and improve the durability of the MEMS device without affecting its performance. Thin coatings deposited with ALD maintain the electrical properties of the MEMS device and its associated shape and geometry so as not to interfere with its functionality. IAD-deposited coatings can have relatively low film stress (e.g., compared to film stress induced by plasma spraying or sputtering). The IAD-deposited coating may additionally have a porosity of less than 1%, and in some embodiments less than about 0.1%. Post-coating heat treatment can be used to achieve improved coating properties. For example, it can be used to convert amorphous coatings into crystalline coatings with higher corrosion resistance. Another example is improving the coating-to-substrate adhesion by forming a reaction zone or transition layer between the coating and the substrate.

[0029] Some implementations also advantageously allow for mounting MEMS devices in a manner that avoids the use of adhesive compounds. For example, in some implementations, the MEMS device may be modified to include a metal strip that surrounds the region of the MEMS device between the sensor region and the interface region for electrical contact, wherein the metal strip is electrically isolated from other conductive components of the MEMS device by a conformal coating formed on the MEMS device. The MEMS device can then be mounted to a metal mounting plate via brazing to form a metal seal between the metal strip of the MEMS device and the mounting plate.

[0030] Several embodiments described herein relate to MFCs or components thereof for limiting the flow rate of gases used in manufacturing systems. However, it should be understood that the embodiments described herein are applicable to purposes other than manufacturing, such as constructing ventilation systems and ventilators for medical use.

[0031] Figure 1A system 100 according to an embodiment of this disclosure is depicted. System 100 includes a processing chamber 101, a gas source 160, and flow control equipment 200. The processing chamber 101 can be used for processing in which a corrosive plasma environment is provided. For example, the processing chamber 101 can be a chamber for a plasma etcher or plasma etching reactor, a plasma cleaner, etc. In alternative embodiments, other processing chambers that may or may not be exposed to a corrosive plasma environment can be used. Some examples of chamber components include chemical vapor deposition (CVD) chambers, physical vapor deposition (PVD) chambers, ALD chambers, IAD chambers, etching chambers, or other types of processing chambers. In some embodiments, the processing chamber 101 can be any chamber used in an electronic device manufacturing system.

[0032] In one embodiment, the processing chamber 101 includes a chamber body 102 enclosing an internal volume 106 and a nozzle 130. The nozzle 130 may include a nozzle base and a nozzle gas distribution plate. Alternatively, the nozzle 130 may be replaced by a cap and nozzle in some embodiments, or by multiple pie-shaped nozzle compartments and a plasma generation unit in other embodiments. The chamber body 102 may be made of aluminum, stainless steel, or other suitable materials such as titanium. The chamber body 102 typically includes sidewalls 108 and a bottom 110.

[0033] The outer liner 116 may be disposed adjacent to 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 made of alumina.

[0034] The exhaust port 126 may be defined within the chamber body 102 and may be coupled to the internal volume 106 to the pump system 128. The pump system 128 may include one or more pumps and throttle valves for evacuating and regulating the pressure of the internal volume 106 of the processing chamber 101.

[0035] A gas source 160 may be coupled to a processing chamber 101 to supply processing and / or cleaning gas to an internal volume 106 via a supply line 112 through a nozzle 130. A flow control device 200 may be coupled to both the gas source 160 and the processing chamber 101. The flow control device 200 may be used to measure and control the gas flow from the gas source 160 to the internal volume 106. An exemplary flow control device 200 is described below in relation to... Figure 2More detailed description. In some embodiments, one or more gas panels may be coupled to processing chamber 101 to supply gas to internal volume 106. In this embodiment, one or more flow control devices 200 may be coupled to each gas source 160 and processing chamber 101. In other embodiments, a single flow control device 200 may be coupled to one or more gas panels. In some embodiments, the flow control device 200 may include a flow ratio controller to control gas flow to processing chamber 101 (e.g., via one or more supply lines 112) or to other processing chambers.

[0036] Nozzle 130 may be supported on the sidewall 108 of chamber body 102. Nozzle 130 (or cover) may be opened to allow access to the internal volume 106 of processing chamber 101 and may provide a seal for processing chamber 101 when closed. Gas source 160 may be coupled to processing chamber 101 to supply processing and / or cleaning gas to the internal volume 106 through nozzle 130 or cover and nozzle (e.g., through orifices in nozzle or cover and nozzle). Nozzle 130 may be used in processing chambers for dielectric etching (etching dielectric materials). Nozzle 130 may include a gas distribution plate (GDP) and may have multiple gas delivery orifices 132 (also referred to as channels) throughout GDP. Nozzle 130 may be formed of a metal or alloy plate protected by a multilayer protective coating as described herein. The metal or alloy plate may be made of aluminum, an aluminum alloy, or another metal or metal alloy. The nozzle 130 can be formed in which GDP is bonded to an aluminum substrate or a cationized aluminum substrate. GDP can be made of Si or SiC, and can be ceramic, such as Y₂O₃, Al₂O₃, or Y₃Al₅O₃. 12 (YAG) etc.

[0037] For processing chambers used for etching conductive materials, a cap can be used instead of a nozzle. The cap may include a central nozzle fitted into a central aperture. The cap may be ceramic, such as Al₂O₃, Y₂O₃, YAG, or a ceramic compound comprising a solid solution of Y₄Al₂O₉ and Y₂O₃-ZrO₂. The nozzle may also be ceramic, such as Y₂O₃, YAG, or a ceramic compound comprising a solid solution of Y₄Al₂O₉ and Y₂O₃-ZrO₂.

[0038] Examples of processing gases that can be used to process the substrate in processing chamber 101 include halogen-containing gases such as C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, and SiF4, and other gases such as O2 or N2O. The flow rate of any of these gases can be measured and regulated by flow control device 200. Remote plasma can be formed from any of these and / or other processing gases and subsequently delivered to processing chamber 101 via supply line 112 and flow control device 200. Thus, remote plasma can be composed of: C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, and SiF4, and other gases such as O2 or N2O. Examples of carrier gases include N2, He, Ar, and other gases inert to the processing gases (e.g., non-reactive gases).

[0039] A substrate support assembly 148 is disposed below the nozzle 130 within the internal volume 106 of the processing chamber 101. The substrate support assembly 148 holds the substrate 144 during processing. A ring (e.g., a single ring) may cover a portion of the electrostatic chuck 150 and protect the covered portion from plasma exposure during processing. In one embodiment, the ring may be silicon or quartz. An inner liner may be coated around the periphery of the substrate support assembly 148. The inner liner may be a halogen-resistant material, such as Al2O3, Y2O3, YAG, ceramic compounds including solid solutions of Y4Al2O9 and Y2O3-ZrO2, other rare-earth-containing or non-rare-earth-containing ceramic materials, or combinations thereof. In one embodiment, the inner liner may be made of the same material as the outer liner 116.

[0040] In some embodiments, one or more sensor devices 170 may be disposed within the internal volume 106. For example, one or more sensor devices 170 may be located near the nozzle 130 (e.g., within 10 cm of the nozzle 130). As another example, one or more sensor devices may be located near the substrate 144 (e.g., within 10 cm of the substrate 144), and these sensor devices may be used to monitor the state near the reaction site.

[0041] In one embodiment, the substrate support assembly 148 includes a base 152 supporting an electrostatic chuck 150. The electrostatic chuck 150 further includes a thermally conductive base and an electrostatic disk bonded to the thermally conductive base by a bonding element, which in one embodiment may be a siloxane bonding element. The thermally conductive base and / or the electrostatic disk of the electrostatic chuck 150 may include one or more optional embedded heating elements, embedded thermal isolators, and / or conduits to control the lateral temperature distribution of the substrate support assembly 148. The electrostatic disk may further include a plurality of gas channels, such as grooves, mesas, and other surface features, that can be formed in the upper surface of the electrostatic disk. The gas channels may be fluidly coupled to a source of heat transfer (or back-side) gas (such as helium) via holes drilled in the electrostatic disk. In operation, back-side gas can be supplied to the gas channels under controlled pressure to enhance heat transfer between the electrostatic disk and the supported substrate 144. The electrostatic chuck 150 may include at least one clamping electrode controlled by a clamping power supply.

[0042] Figure 2 A flow control device 200 according to an embodiment of this disclosure is depicted. The 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 can therefore be considered a type of MFC. The flow control device 200 can be coupled to a gas source 160 and a processing chamber 101 via a gas flow channel 240. The gas flow channel can correspond to... Figure 1 Supply line 112. In some embodiments, the flow control device 200 may be integrated into a flow ratio controller or a pulsed mass flow system.

[0043] In some embodiments, the flow control device 200 may include at least a flow regulator 210, a sensor device 220, and a processing device 230. Gas from the gas source 160 flows through a flow path 242 (defined by a gas flow channel 240), through the flow regulator 210, and into the processing chamber 101. In other embodiments, the gas flow channel 240 may terminate somewhere other than the processing 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).

[0044] In some embodiments, the flow regulator 210 is configured to restrict gas flow through the flow path 242 and may include one or more flow regulating valves, each of which may be an actuable valve, such as, for example, a solenoid valve or a piezoelectric valve. In some embodiments, the flow regulator includes components other than valves, such as flow or temperature sensing components. In some embodiments, the flow regulator 210 is used as an MFC, such as a heat-based MFC, a pressure-based MFC, or a decay rate-based MFC.

[0045] In some embodiments where the flow regulator 210 is used as a heat-based MFC, the flow regulator 210 includes a capillary bypass channel branching 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 increment that is proportional to the gas flow rate.

[0046] In some embodiments where the flow regulator 210 is used as a pressure-based MFC, the flow regulator 210 includes two pressure transducers upstream and downstream of the flow control valve and temperature sensor. The gas flow rate is proportional to the product of the temperature and the squared difference between the upstream and downstream pressures.

[0047] In some embodiments where the flow regulator 210 is used as a decay rate-based MFC, the flow regulator 210 includes a valve for controlling gas flow into a reservoir of a predetermined volume, and a pressure sensor for measuring the decay pressure in the reservoir. The gas flow rate is proportional to the rate of pressure change.

[0048] In some embodiments, the sensor device 220 is disposed downstream of the flow regulator 210. The sensor device 220 may be part of the flow regulator 210 (e.g., a flow control valve adjacent to the flow regulator 210), near the flow regulator 210 (e.g., within 10 cm of the flow regulator 210), near the inlet of the processing chamber 101 or the nozzle 130 (e.g., within 10 cm of the inlet), or within the processing chamber 101 (e.g., within 10 cm of the inlet). Figure 1 The diagram shows sensor device 170, which may be the same as or similar to sensor device 220.

[0049] In some embodiments, sensor device 220 includes a MEMS device 222 that may be configured to generate one or more signals in response to the state of gas flow. For example, MEMS device 222 may be configured to generate one or more signals indicating gas temperature or gas flow rate. Exemplary MEMS devices are described in more detail below with reference to FIG3. In some embodiments, sensor device 220 is mounted to gas flow channel 240 such that MEMS device 222 is directly inserted into flow path 242. Sensor device 220 is coupled to gas flow channel such that a seal is formed to prevent gas leakage. In some embodiments, sensor device 220 includes a mounting plate to which MEMS device 222 is secured via a seal (e.g., a metal seal).

[0050] In some embodiments, processing device 230 includes a central processing unit (CPU), microcontroller, programmable logic controller (PLC), system-on-a-chip (SoC), server computer, or other suitable type of computing device. Processing device 230 may be configured to execute programmed instructions relating to the operation of flow regulator 210. Processing device 230 receives feedback signals from sensor device 220 and optionally from flow regulator 210, and calculates the temperature, flow rate, and / or other parameters of the gas flow. Processing device 230 further sends control signals to flow regulator 210 based on the received feedback signals. In some embodiments, processing device 230 is configured for high-speed feedback processing and may include, for example, EPM. In some embodiments, processing device 230 is configured to execute a processing recipe, or one or more steps of a processing recipe, for a manufacturing process using processing chamber 101. For example, a recipe may specify a gas flow at a specific time, for a specific duration, or for a specific gas at a specific flow rate. As another example, a recipe may specify a pulse of one or more gases.

[0051] Figure 3A and Figure 3B Top and side views of an exemplary MEMS device 300 according to embodiments of the present disclosure are shown, which is manufactured using semiconductor manufacturing techniques known to those skilled in the art. The MEMS device 300 can be used with... Figure 2The MEMS device 222 described is the same as or similar to this one. The overall dimensions of the MEMS device 300 can be characterized by the following: a length (L) from about 2 mm to about 10 mm, a width (W) from about 1 mm to about 5 mm, and a thickness (T) from about 0.1 mm to about 1 mm. The MEMS device 300 includes an elongated support structure 302 having a substantially flat shape. The elongated support structure 302 can be formed of an insulating material or a semiconductor, such as silicon, silicon with one or more oxide layers formed thereon, or any other suitable material. The elongated support structure 302 may have a tapered shape that improves its aerodynamic properties. The tapered region may further define a cavity 306 on which freestanding sensing elements (such as nanowires 308) are suspended.

[0052] Electrodes 304 are shown disposed on the surface of an elongated support structure 302, extending from a flat end of the elongated support structure 302 to the nanowire 308. Electrodes 304 may be formed of one or more conductive metals. The electrodes may serve as electrical contacts to which one or more devices (e.g., processing device 230) are operatively coupled. In some embodiments, a portion of the electrode 304 may be encapsulated within or formed through the interior of the elongated support structure 302 to protect the electrode 304 from corrosion.

[0053] Figure 3C An enlarged view of a nanowire 308 suspended between two electrodes 304 is shown. As used herein, the term "nanowire" refers to a conductive body having at least two dimensions of less than 1 micrometer. In some embodiments, the nanowire 308 is formed of the same conductive material as the electrodes 304, such as platinum. For example, the nanowire 308 may be formed by depositing a metal (e.g., platinum) onto an elongated support structure 302 and selectively etching the elongated support structure 302, thereby causing the freestanding nanowire 308 to be suspended on a cavity 306. In some embodiments, the nanowire 308 may be a single continuous filament, but may also be formed from nanoparticles or nanotubes arranged to form a conductive route. Other continuous or discontinuous structures may be used, provided that impedance measurements across the line are permitted.

[0054] Nanowire 308 is fabricated to have a length (L) greater than its diameter or width / thickness. w The nanowires 308 are sized such that they can deflect when exposed to low and high velocity gas flows. In some embodiments, L w The length is less than 1 millimeter, for example, from about 1 micrometer to about 500 micrometers, or from about 10 micrometers to about 200 micrometers. In some embodiments, L wThe nanowire 308 may be approximately 10 to approximately 100,000 times larger than its diameter or width / thickness. In some embodiments, the nanowire 308 may have a circular or rectangular cross-section having a diameter or thickness / width of approximately 50 nanometers to approximately 500 nanometers. Those skilled in the art will recognize that other sizes may be available.

[0055] In some implementations, the MEMS device 300 may be configured to provide multiple sensor modes with different sensitivities along different dimensions. For example, the MEMS device 300 may be configured for a constant current anemometer (CCA), wherein a fixed current is passed through nanowires 308 to raise the temperature of the nanowires 308, thereby increasing resistance. During operation, gas flow above the wires removes heat from the nanowires 308 via convection, and the resistance will reach a steady state under constant current and constant gas velocity. An increase or decrease in gas velocity will respectively cause a decrease or increase in the resistance of the nanowires 308, thereby allowing the measured voltage output to be correlated with the gas flow rate.

[0056] As another example, the MEMS device 300 can be configured for elastic filament velocimetry (EFV). The gas velocity can be correlated with the strain in the nanowire 308 caused by the gas flow. In this operation, a small current can flow through the nanowire 308, resulting in negligible heating. During operation, the gas flow deflects the nanowire 308, thereby causing internal stress that changes the resistance of the nanowire 308. This change in resistance can be correlated with the gas flow rate.

[0057] In some embodiments, nanowires 308 may be combined on a MEMS device 300, wherein two or more nanowires have separate electrode pairs, each of which can be used to separately perform CCA or EFV. In some embodiments, the two or more nanowires may be oriented in a non-collinear orientation.

[0058] Figure 4A Figures A and B respectively show a top view and a side view of an exemplary MEMS device 400 suitable for use in a flow control device (e.g., flow control device 200) according to embodiments of the present disclosure. The MEMS device 400 corresponds to a modification of the MEMS device 300, which includes a metal strip 410 and may also include a non-conductive conformal coating 420 (as described below). Figure 4C (Description). The elongated support structure 302 includes three regions. The first region is an interface region 402 for coupling the MEMS device 400 to an external device (such as the processing device 230). Electrodes 304 can be used as electrical contacts for mating with such external devices, thereby forming a closed circuit during operation.

[0059] The second region is a coupling region 404, serving as a location for the MEMS device 400 to be coupled or mounted to another structure (such as a mounting plate). A metal strip 410 is located at the coupling region, which is substantially situated at the center of the elongated support structure 302. In some embodiments, the metal strip 410 is located at another suitable location on the elongated support structure 302, provided that the metal strip 410 does not overlap with the cavity 306 or obstruct the electrical coupling of the electrode 304.

[0060] In some embodiments, the metal strip 410 is formed of nickel, aluminum, another non-corrosive metal, or an alloy thereof. In some embodiments, the metal strip 410 may be deposited using techniques such as physical vapor deposition (PVD) or electroplating to deposit a continuous conformal layer that surrounds a portion of the elongated support structure 302. Figure 4A and Figure 4B The diagram shows a conformal layer covering multiple surfaces of the elongated support structure 302. Figure 4A In the diagram, the dashed line passing through the metal strip 410 indicates that the indicator electrode 304 is disposed below the metal strip 410. In some embodiments, an insulating layer (e.g., SiO2) is deposited before the metal strip 410 to separate the metal strip 410 from the elongated support structure 302 and the electrode 304, in order to avoid short circuits between the electrodes 304 during operation. In some embodiments, the thickness of the metal strip 410 is from 50 micrometers to 500 micrometers. In some embodiments, the width of the metal strip (i.e., the width measured along the longitudinal axis of the elongated support structure 302) is from 0.5 millimeters to 2 millimeters. In some embodiments, the metal strip 410 does not form a continuous layer and may, for example, be deposited as discrete islands of metallic material.

[0061] In some embodiments, the MEMS device 400 further includes a non-conductive conformal coating 420 on one or more surfaces or portions thereof of the interface region 402, coupling region 404, and / or sensor region 406. In some embodiments, the conformal coating 420 covers some or all of the sensor region 406, including some or all of the nanowires 380. In other embodiments, the conformal coating 420 covers the sensor region 406 but not the nanowires 380. In other embodiments, the conformal coating 420 covers only the portions of the MEMS device 400 exposed to gas flow when the MEMS device 400 is inserted into a gas flow channel, as described below. Figure 5A To the 5G discussion.

[0062] In some embodiments, the conformal coating 420 covers at least a portion of the coupling region 404 and / or the interface region 402. In some embodiments, a metal strip 410 is disposed on the conformal coating 420, wherein the conformal coating 420 serves as an insulating layer between the metal strip 410 and the electrode 304. In this embodiment, the conformal coating 420 is deposited prior to the deposition of the metal strip 410.

[0063] Figure 4C A magnified cross-sectional view of a region of the MEMS device 400 is shown to illustrate conformal coatings 420 on multiple surfaces of the elongated support structure 302. In some embodiments, the conformal coating 420 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 the conformal coating or modifications thereof. In some embodiments, the conformal coating 420 comprises a ceramic material resistant to corrosion by process gases or reactive substances. For example, in some embodiments, the conformal coating may comprise a plasma-resistant ceramic coating comprising rare earth ceramics selected from Y₂O₃, YZrO, Y₂O₃ ... x Zr y O z YZrOF, Y3Al5O 12 Y4Al2O9, YF3, Y x O y F z YOF, Er2O3, Er3Al5O 12 ErF3, E x O y F z ErOF, La2O3, Lu2O3, Sc2O3, ScF3, ScOF, Gd2O3, Sm2O3, Dy2O3, Y2O3-ZrO2 solid solutions, ceramics containing Y2Al4O9 and Y2O3-ZrO2 solid solutions, or combinations thereof. In some embodiments, the conformal coating 420 is substantially uniform, conformal, and non-porosity.

[0064] like Figure 4CAs shown, in some embodiments, the conformal coating 420 comprises a plurality of layers 422A-422D deposited sequentially. In some embodiments, more or fewer layers may be provided compared to the illustrated case, and the number of layers may vary from 1 to 100, up to 500, or more. For example, multiple atomic-level or near-atomic-level thin layers may be deposited, for example, using ALD deposition. In some embodiments, the composition of each of layers 422A-422D may be alternating. In some embodiments, the total thickness of the conformal coating 420 may vary from 10 nanometers to 300 nanometers.

[0065] Figures 5A to 5E The illustration shows a MEMS device 400 mounted to an exemplary mounting plate 500 according to an embodiment of this disclosure. The mounting plate 500 may be in the form of a thin, flat sheet of metal, although other suitable shapes such as circular, rectangular, etc., are also considered. In some embodiments, the thickness of the mounting plate may vary from 500 micrometers to 5 millimeters. The mounting plate 500 may be formed of, for example, stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, which is an alloy of nickel, molybdenum, and chromium), or another suitable material. The mounting plate 500 includes a slot 502 formed therethrough, the shape of which is for receiving the MEMS device 400. In some embodiments, the slot 502 is sized such that it does not physically contact the MEMS device 400 (or at least a portion of the MEMS device 400). Figure 5C and Figure 5D As shown, the MEMS device 400 can be inserted into a slot 502 and subsequently mounted to the mounting surface 500B of the mounting plate 500, for example, via a seal 510 formed between the metal strip 410 and the mounting plate 500. The seal 510 is an airtight seal used to prevent gas leakage when the mounting plate 500 and components of the MEMS device 400 are further coupled to a gas flow channel (such as a gas flow channel 520). In some embodiments, the seal 510 is a metal seal formed, for example, by brazing or welding.

[0066] Figure 5F A cross-sectional view of the components coupled to the mounting plate 500 and the MEMS device 400, which are similar to those of the gas flow channel 520, is shown. Figure 2 The diagram shows a configuration in which sensor device 220 is coupled to gas flow channel 240. In some embodiments, gas flow channel 520 is a gas line, a branch channel of a gas line, or has separate components for mounting to an inlet and outlet of a gas line. In some embodiments, a mounting plate is integrally formed with gas flow channel 520. In some embodiments, mounting plate 500 is mechanically coupled to gas flow channel.

[0067] When the mounting plate 500 is coupled to the gas flow channel 520, the MEMS device 400 is inserted through the slot 522 of the gas flow channel 520, such that the nanowire 308 is positioned within the flow path 530 of the gas flow channel 520 (which is in a direction orthogonal to the drawing plane). When the mounting plate 500 is in a planar configuration, as shown, a rubber O-ring 540 may be disposed between the gas-facing surface 500A of the mounting plate 500 and the gas flow channel 520 to form a seal. The wire 550 may be mechanically coupled or soldered, for example, to the electrode 304 of the MEMS device 400 to operatively couple the MEMS device 400 to, for example, a processing device 230.

[0068] Figure 6 A method 600 for adapting a sensor device for use in a flow control device according to an embodiment of this invention is shown. In block 610, a sensor device, such as those described above, is provided. Figure 2 The described sensor device 220. In some embodiments, the sensor device includes a MEMS device, such as... Figure 2 Referring to the MEMS device 222 or 300 depicted in Figure 5. In some embodiments, the sensor device includes an elongated support structure comprising an interface region (e.g., interface region 402), a sensor region (e.g., sensor region 406), and a coupling region (e.g., coupling region 404) located between the interface region and the sensor region. The sensor region includes a freestanding sensing element, such as a nanowire (e.g., nanowire 308), suspended therefrom.

[0069] In block 620, a conformal coating (e.g., conformal coating 420) is deposited onto the sensor device to at least partially coat the sensor area. 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 nanowire (e.g., nanowire 308). In other embodiments, the conformal coating covers the sensor area and does not coat or minimally coats the nanowire.

[0070] In some embodiments, the conformal coating is deposited using one or more of the following methods: ALD, IAD, LPPS, CVD, PS-CVD, or sputtering. In some embodiments, the conformal coating comprises rare earth ceramics selected from the following: Y₂O₃, YZrO, Y x Zr y O z YZrOF, Y3Al5O 12 Y4Al2O9, YF3, Y x O y F z YOF, Er2O3, Er3Al5O 12ErF3, E x O y F z The conformal coating comprises ErOF, La2O3, Lu2O3, Sc2O3, ScF3, ScOF, Gd2O3, Sm2O3, Dy2O3, Y2O3-ZrO2 solid solutions, ceramics containing Y2Al4O9 and Y2O3-ZrO2 solid solutions, or combinations thereof. In some embodiments, the conformal coating comprises multiple layers. In some embodiments, the conformal coating has a thickness of about 10 nanometers to about 300 nanometers.

[0071] In block 630, a metal strip (e.g., metal strip 410) is deposited on the sensor device (i.e., on the MEMS device). In some embodiments, the metal strip is deposited using one or more of PVD or electroplating. In some embodiments, the metal strip forms a continuous conformal layer that surrounds a portion of an elongated support structure. In some embodiments, the metal strip is deposited over a conformal coating. In other embodiments, a conformal coating is not present at the location where the metal strip is deposited or otherwise formed.

[0072] In block 640, the sensor device is secured to a mounting plate (e.g., mounting plate 500). In some embodiments, the sensor device is secured to the mounting plate by forming a metal seal (e.g., seal 510) between the metal strip and the mounting plate, for example by brazing or welding. In some embodiments, the sensor device is inserted into a gas flow channel and the mounting plate is mechanically coupled to the gas flow channel (e.g., Figure 5F (As shown in the image).

[0073] For the sake of simplicity, the methods of this disclosure are depicted and described as a series of actions. However, the actions according to this disclosure can occur in any order and / or simultaneously, and other actions are not presented or described herein. Furthermore, not all actions shown are required to implement the methods according to the disclosed subject matter. Moreover, those skilled in the art will understand and recognize 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 writing to facilitate the transfer and transmission of instructions for performing such methods to a computing device. As used herein, the term "article of writing" is intended to encompass a computer program accessible from any computer-readable device or storage medium.

[0074] Figure 7A graphical representation of a machine in an exemplary form of computer system 700 is shown, wherein an executable set of instructions (e.g., for causing the machine to perform any or more methods discussed herein) is provided. In alternative embodiments, the machine may be connected (e.g., network-connected) 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, network device, server, network router, switch or bridge, or any machine capable of executing a set of instructions (continuously or otherwise) specifying actions to be taken by the machine. Furthermore, although only a single machine is shown, the term "machine" should also be considered to include any collection of multiple machines that independently or jointly execute a set of instructions (or multiple sets of instructions) to perform any or more methods discussed herein. Some or all of the components of the computer system 700 may be utilized by or describe any electronic component described herein (e.g., processing device 230 or any electronic component used in conjunction with the operation of processing chamber 101 or flow regulator 210).

[0075] An exemplary computer system 700 includes a processing device (processor) 702, a main memory 704 (e.g., ROM, flash memory, dynamic random access memory (DRAM, such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM)), a static memory 706 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 720, which communicate with each other via a bus 710.

[0076] Processor 702 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, or the like. More specifically, processor 702 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 other instruction sets or combinations of instruction sets. Processor 702 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 702 is configured to execute instructions 740 for performing the operations discussed herein.

[0077] The computer system 700 may further include a network interface device 708. The computer system 700 may also include a video display unit 712 (e.g., a liquid crystal display (LCD), a cathode ray tube (CRT), or a touch screen), an alphanumeric input device 714 (e.g., a keyboard), a cursor control device 716 (e.g., a mouse), and a signal generation device 722 (e.g., a speaker).

[0078] Power device 718 can monitor the power level of the battery used to power computer system 700 or one or more of its components. Power device 718 may provide one or more interfaces for providing indications of: power level, remaining time window before shutting down computer system 700 or one or more of its components, power consumption rate, whether the computer system is using external power or battery power, and other power-related information. In some implementations, the indications regarding power device 718 may be remote (e.g., accessed via a network connection to a remote backup management module). In some implementations, the battery used by power device 718 may be an uninterruptible power supply (UPS) at the local or remote end of computer system 700. In this implementation, power device 718 may provide information regarding the power level of the UPS.

[0079] Data storage device 720 may include computer-readable storage medium 724 (e.g., a non-transitory computer-readable storage medium) on which one or more sets of instructions 740 (e.g., software) embodying any one or more methods or functions described herein may be stored. These instructions 740 may also reside wholly or at least partially within main memory 704 and / or processor 702, which also constitute the computer-readable storage medium, during their execution. The instructions 740 may further be transmitted or received over network 730 (e.g., network 14) via network interface device 708. Although computer-readable storage medium 724 is illustrated as a single medium in the exemplary implementation, it will be understood that computer-readable storage medium 724 may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) storing one or more sets of instructions 740.

[0080] Several details have been set forth in the foregoing description. However, it will be apparent to those skilled in the art who will benefit from this disclosure that embodiments of this disclosure can be practiced without these specific details. Although specific embodiments have been described herein, it should be understood that these embodiments are presented by way of example only and are not intended to be limiting. The breadth and scope of this application should not be limited to any of the embodiments described herein, but should be defined solely by the appended and subsequently filed claims and their equivalents. In fact, various other implementations and modifications of this disclosure besides those described herein will be apparent to those skilled in the art from the foregoing description and drawings. Therefore, such other implementations and modifications are intended to fall within the scope of this disclosure.

[0081] Referring to the accompanying drawings, which form part of the description, and in which specific embodiments are illustrated by way of illustration. While these disclosed embodiments are described in sufficient detail to enable those skilled in the art to practice them, it will be understood that these examples are not limiting, allowing other embodiments to be used and modifications to be made to the disclosed embodiments without departing from their spirit and scope. For example, the blocks of the methods illustrated and described herein need not be performed in the order indicated 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, in some other embodiments, the content of a single block may be implemented in multiple blocks. Moreover, unless otherwise indicated, the conjunction “or” is intended to have an inclusive meaning herein; that is, the phrase “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.”

[0082] The terms “example” or “exemplary” are used herein to mean as an example, instance, or illustration. Any aspect or design described herein as an “example” or “exemplary” is not to be construed as superior or advantageous over other aspects or designs. Rather, the use of the terms “example” or “exemplary” is intended to present concepts in a specific manner, and when the terms “about” or “approximately” are used herein, it is intended to mean that the nominal values ​​presented are exactly within ±10%.

[0083] Furthermore, the article “a” (“a” and “an”) used herein and in the appended claims should generally be interpreted as meaning “one or more”, unless otherwise stated or clearly indicated in the context as a singular form. References to “an embodiment,” “one embodiment,” “some embodiments,” or “certain embodiments” throughout this specification indicate that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, the phrases “an embodiment,” “one embodiment,” “some embodiments,” or “certain embodiments” appearing in various places throughout this specification do not necessarily refer to the same embodiment.

[0084] Some parts of the detailed description can be presented in terms of algorithms and symbolic representations of operations on data bits within computer memory. These algorithms and representations are the methods used by those skilled in the art of data processing to most effectively communicate the essence of their work to others skilled in the art. Algorithms are, and are generally considered herein, a self-consistent sequence of steps that leads to the desired result. These steps are those that require physical manipulation of physical quantities. This is usually, though not always, in the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, or otherwise manipulated. It has proven convenient, primarily for general reasons, to refer to these signals as bits, values, elements, symbols, characters, items, numbers, or the like.

[0085] However, it should be remembered that all these and similar terms will be associated with appropriate physical quantities and will only be used for convenient labeling of those quantities. Unless otherwise specifically stated, it will be understood from the following discussion that throughout the description, the use of terms such as “receive,” “retrieve,” “send,” “calculate,” “generate,” “process,” “reprocess,” “add,” “subtract,” “multiply,” “divide,” “optimize,” “calibrate,” “detect,” “execute,” “analyze,” “determine,” “enable,” “identify,” “modify,” “transform,” “apply,” “cause,” “store,” “compare,” or similar terms refers to the manipulation and transformation of data representing physical (electronic) quantities in the registers and memories of a computer system into other data representing physical quantities similarly represented in the memory or registers or other such information storage, transmission, or display devices of a computer system.

[0086] Furthermore, although this disclosure has been described herein in the context of a particular implementation in a particular setting for a particular purpose, those skilled in the art will recognize that its use is not limited thereto and that this disclosure can be beneficially implemented for any number of purposes in any number of settings. Therefore, the claims set forth herein should be interpreted in accordance with the full breadth and spirit of this disclosure as described herein, together with the full scope of the equivalents of such claims.

Claims

1. A sensor device, comprising: An elongated support structure comprising an interface region, a sensor region, and a coupling region between the interface region and the sensor region, wherein the elongated support structure is composed of a non-solderable material; An electrode, wherein the electrode is disposed on the interface region; A stand-alone sensing element, suspended in the sensor region, wherein the stand-alone sensing element is electrically coupled to the electrode; A conformal strip metal coating surrounds the coupling region, wherein the conformal strip metal coating seals to the coupling region of the elongated support structure, and wherein the conformal strip metal coating is brazable and capable of brazing the elongated support structure to a mounting plate to form a metal seal between the sensor device and the mounting plate. as well as A non-conductive conformal coating is applied to at least a portion of the sensor region, the non-conductive conformal coating comprising a plasma-resistant ceramic material.

2. The sensor device of claim 1, wherein the sensor device comprises a silicon-based microelectromechanical system (MEMS) device.

3. The sensor device according to claim 1, wherein the non-conductive conformal coating has a thickness of 10 nanometers to 300 nanometers.

4. The sensor device of claim 1, wherein the freestanding sensing element comprises a nanowire, and wherein the sensor region defines a cavity on which the nanowire is suspended.

5. The sensor device of claim 4, wherein the nanowire comprises platinum, and wherein the nanowire is at least partially coated with the non-conductive conformal coating.

6. The sensor device of claim 1, wherein the electrode is formed on or within the coupling region, and wherein the non-conductive conformal coating forms an insulating layer between the conformal strip metal coating and the electrode.

7. The sensor device of claim 1, wherein the mounting plate further comprises: A gas-facing surface and a mounting surface opposite to the gas-facing surface, the mounting plate having a slot formed therethrough, wherein... The elongated support structure is disposed in the slot such that the sensor region extends from the gas-facing surface and the coupling region extends from the mounting surface. The elongated support structure is secured to the mounting plate at the coupling area by a metal seal formed between the conformal strip metal coating and the mounting surface of the mounting plate.

8. A flow control device, comprising: Gas flow channel, which defines the gas flow path; A flow control valve, the flow control valve being configured to regulate the gas flow in the gas flow passage; Sensor device, the sensor device comprising: An elongated support structure, wherein the elongated support structure is composed of a non-brazable material; The sensor region is located on the elongated support structure, and the sensor region includes a non-conductive conformal plasma-resistant ceramic coating disposed within the gas flow path and a freestanding sensing element. as well as A coupling region located on the elongated support structure, wherein the coupling region includes a conformal strip metal coating that seals the sensor device to the gas flow channel, wherein the conformal strip metal coating seals to the coupling region, and wherein the conformal strip metal coating is brazable and capable of brazing the elongated support structure to an external region of the mounting plate or the gas flow channel to form a metal seal between the sensor device and the external region of the mounting plate or the gas flow channel; as well as A processing device operatively coupled to the flow control valve and the sensor device, the processing device being configured to regulate the flow control valve based on a signal received from the sensor device.

9. The flow control device according to claim 8, wherein the sensor device is a silicon-based microelectromechanical system (MEMS) device.

10. The flow control device of claim 8, wherein the freestanding sensing element comprises nanowires.

11. The flow control device of claim 8, wherein the freestanding sensing element is at least partially coated with the non-conductive conformal plasma-resistant ceramic coating.

12. The flow control device according to claim 8, wherein the elongated support structure is disposed within a slot formed in the gas flow path.

13. The flow control device of claim 12, wherein the coupling region corresponds to a portion of the slot extending from the elongated support structure into the gas flow path, wherein the sensor device is fixed to the gas flow path by the mounting plate, the mounting plate being mechanically coupled to the gas flow path.

14. The flow control device of claim 12, wherein the coupling region corresponds to a portion of the slot extending from the elongated support structure into the gas flow channel, wherein the sensor device is fixed to the gas flow path through the outer region of the gas flow channel.

15. A method for adapting a sensor device for use in a flow control device, the method comprising the steps of: The sensor device is provided, the sensor device comprising: An elongated support structure comprising an interface region, a sensor region, and a coupling region between the interface region and the sensor region, wherein the elongated support structure is composed of a non-solderable material; as well as A stand-alone sensing element, which is suspended in the sensor area; A conformal coating is deposited on the sensor device to at least partially cover the sensor region, the conformal coating comprising a plasma-resistant ceramic material; as well as A conformal strip metal coating is deposited on the sensor device to surround the coupling region, wherein the conformal strip metal coating seals to the coupling region of the elongated support structure, and wherein the conformal strip metal coating is brazable and capable of brazing the elongated support structure to a mounting plate to form a metal seal between the sensor device and the mounting plate.

16. The method of claim 15, wherein the conformal coating is deposited using an ion-assisted deposition process, and wherein the plasma-resistant ceramic material is non-conductive.

17. The method of claim 15, further comprising the following steps: A metal seal is formed between the conformal strip metal coating and the mounting plate to secure the sensor device to the mounting plate.

18. The method of claim 17, wherein the metal seal is formed by brazing.

19. The method of claim 17, further comprising the step of: Insert the sensor device into the gas flow channel; and The mounting plate is mechanically coupled to the gas flow channel.

20. The sensor device of claim 1, wherein the conformal strip metal coating has a thickness of 50 micrometers to 500 micrometers and a width of 0.5 millimeters to 2 millimeters.

Images