Microelectromechanical devices for use in flow control devices - Patents.com

Abstract

Disclosed herein are embodiments of a sensor device, a system incorporating the same, and a method of manufacturing the same. In one embodiment, the sensor device includes a freestanding sensing element, such as a microelectromechanical systems (MEMS) device. The sensor device further includes a metal band that facilitates mounting the MEMS device to a mounting plate. The sensor device further includes a conformal coating on at least a portion of a sensor area of ​​the sensor device.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure generally relate to methods and apparatus for monitoring and controlling the flow rate of a gas. [Background technology]

[0002] Controlling the flow rate of gases presents 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 to clean manufactured devices and / or chambers used in the manufacture of electronic devices) may have precise delivery targets, including the ability to precisely control high mass flow rates (i.e., 500 standard liters per minute or more) and low flow rates (i.e., 10 standard liters per minute or less). Conventional manufacturing systems often use one or more mass flow controllers (MFCs) to measure and control the mass flow rates of process gases.

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

[0004] Certain embodiments of the present disclosure relate to sensor devices, systems incorporating sensor devices, and methods of adapting sensor devices for use in flow control devices. In one aspect of the disclosure, the sensor device includes an elongated support structure, an electrode, and a free-standing sensing element. The elongated support structure includes an interface region, a sensor region, and a connection region positioned between the interface region and the sensor region. The electrode is disposed in the interface region, and the free-standing sensing element is suspended over the sensor region and electrically connected to the electrode. In some embodiments, the sensor device comprises a metal band surrounding the connection 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 microelectromechanical systems (MEMS) device.

[0005] In another aspect of the disclosure, a flow control device includes a gas flow channel defining a gas flow path, a flow regulating valve configured to regulate a gas flow in the gas flow channel, a sensor device including a free-standing sensing element, and a processing device. In some embodiments, the free-standing sensing element is disposed in the gas flow path. In some embodiments, the processing device is operably connected to the flow regulating valve and the sensor device and configured to control the flow regulating valve based on a signal received from the flow sensor device. In some embodiments, the sensor device includes a microelectromechanical systems (MEMS) device.

[0006] In another aspect of the disclosure, a method of adapting a flow sensor device for use in a gas flow channel includes providing a sensor device, depositing a conformal coating on the sensor device to at least partially cover a sensor region of the sensor device, and depositing a metal band on the sensor device to surround a connection region of the sensor device. In some embodiments, the sensor device comprises an elongated support structure including an interface region, a sensor region, and a connection region positioned between the interface region and the sensor region.

[0007] The present disclosure is described, by way of non-limiting example only, with reference to the accompanying drawings, in which like elements are designated with like reference numerals, and in which: Figure 1 is a schematic diagram of a method for manufacturing a semiconductor device according to the present invention; [Brief description of the drawings]

[0008] [Figure 1] 1 is an exemplary system including a processing chamber, a gas source, and a flow controller according to an embodiment of the present disclosure. [Diagram 2] 1 is an exemplary flow control device according to an embodiment of the present disclosure. [Figure 3A] FIG. 2 is a top view of an exemplary MEMS device in accordance with an embodiment of the present disclosure. [Figure 3B] 1 is a side view of an exemplary MEMS device in accordance with an embodiment of the present disclosure. [Figure 3C] 1 is an exemplary MEMS device free-standing sensing element according to an embodiment of the present disclosure. [Figure 4A] FIG. 2 is a top view of an exemplary MEMS device adapted for use in a flow control device, according to an embodiment of the present disclosure. [Figure 4B] FIG. 2 is a side view of an exemplary MEMS device adapted for use in a flow control device according to an embodiment of the present disclosure. [Figure 4C] 1 is a cross-sectional view of a conformal coating formed on a surface of an exemplary MEMS device in accordance with an embodiment of the present disclosure. [Figure 5A] FIG. 13 is a top view of an exemplary mounting plate according to an embodiment of the present disclosure. [Figure 5B] FIG. 13 is a cross-sectional side view of an exemplary mounting plate according to an embodiment of the present disclosure. [Figure 5C] 1 illustrates an exemplary MEMS device prior to insertion through a slot in an exemplary mounting plate, in accordance with an embodiment of the present disclosure. [Figure 5D]1 illustrates an exemplary MEMS device inserted into a slot of an exemplary mounting plate, according to an embodiment of the present disclosure. [Figure 5E] 1 illustrates an exemplary MEMS device mounted in a slot of an exemplary mounting plate by a metal seal, in accordance with an embodiment of the present disclosure. [Figure 5F] 1 illustrates an exemplary MEMS device connected to a gas flow channel via an exemplary mounting plate, according to an embodiment of the present disclosure. [Figure 6] 1 is a method of adapting a sensor device for use in a flow control device according to an embodiment of the present disclosure. [Figure 7] FIG. 1 is a block diagram illustrating a computer system for use according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The embodiments described herein relate to a sensor device adapted for use in a mass flow controller, a system incorporating the same, and a method of adapting the sensor device for such use. The sensor device, in some embodiments, includes a MEMS device having a free-standing sensing element that is to be placed directly in the flow path of a gas flow channel. The MEMS device has formed thereon a conformal coating to protect the MEMS device from corrosive gases, and a metal band that allows a metal seal to be formed between the MEMS device and a mounting plate or other device or structure to which the MEMS device is attached.

[0010] It is generally advantageous to precisely control the flow rate of process gases used in manufacturing processes to allow for better control of the process and to meet precise processing constraints. The slow transient response speeds of current MFCs, typically on the order of 100 milliseconds or more, are inadequate for applications requiring precise control of gas dosing, such as the delivery of small amounts of gas, as well as one or more pulses of gas in succession having pulse widths on the order of 100 milliseconds or less.

[0011] The embodiments of the present disclosure advantageously overcome the limitations of current MFCs by utilizing a MEMS device directly in the gas flow path to provide fast (i.e., less than about 1 millisecond transient response) and accurate flow feedback. A processing device, such as an EtherCAT® Plug-in Module (EPM), operably connected to the MEMS device can more quickly control the MFC or a stand-alone actuable valve based on the fast flow feedback compared to conventional MFCs. While various embodiments may utilize a MEMS device as the sole source of feedback, flow feedback from the MFC device may also be advantageously used in conjunction with the MEMS feedback, for example, for calibration or validation purposes (e.g., to ensure consistency between measured signals).

[0012] In addition to flow rate feedback, MEMS devices may be advantageously utilized to provide fast and accurate temperature measurements anywhere in the gas supply line, including at the source, near a valve, near the inlet to the processing chamber (i.e., the delivery point), or within the processing chamber. The temperature measurements may be monitored in real time by the processing device, which can send power output commands to heating units at different points in the gas supply line.

[0013] Certain embodiments advantageously adapt the MEMS device to be inserted directly into a gas flow path while protecting the MEMS device from the corrosive effects of the gas. For example, in some embodiments, a protective and non-conductive conformal coating is deposited on the surface of the MEMS device that is exposed to the gas during operation. For example, atomic layer deposition (ALD) or ion-assisted deposition (IAD) techniques can be utilized to form a conformal coating on at least a portion of the MEMS device. ALD techniques allow for conformal coatings of substantially uniform thickness and zero porosity (i.e., no porosity) on all exposed surfaces of the covered components, including, for example, features with complex geometries and / or high aspect ratios. The coatings can be plasma resistant to reduce plasma interactions and improve the durability of the MEMS device without affecting its performance. ALD-deposited thin coatings can maintain the electrical properties, relative shape, and geometric configuration of the MEMS device so as not to interfere with the function of the MEMS device. IAD-deposited coatings can have relatively low film stress (e.g., compared to film stress caused by plasma spraying or sputtering). The IAD deposited coating may further have a porosity of less than 1%, and in some embodiments, less than about 0.1%. Post-coating heat treatments can be used to improve coating properties. For example, they can be used to convert an amorphous coating to a crystalline coating that has higher erosion resistance. Another example is to improve the bond strength of the coating to the substrate by forming a reaction zone or transition layer between them.

[0014] Certain embodiments also advantageously allow for mounting the MEMS device in a manner that avoids the use of adhesive compounds. For example, in certain embodiments, the MEMS device may be modified to include a metal band that surrounds the area of ​​the MEMS device between the sensor area and the interface area where electrical contact is made, the metal band being electrically insulated from other conductive components of the MEMS device by a conformal coating formed on the MEMS device. The MEMS device may then be attached to a metal mounting plate by brazing to form a metal seal between the metal band of the MEMS device and the mounting plate.

[0015] Some embodiments herein are described with respect to MFCs or components thereof being used to limit the flow rate of gases used in manufacturing systems, however, it should be understood that the embodiments described herein also apply to other purposes outside of manufacturing, such as building ventilation systems and medical ventilators.

[0016] FIG. 1 illustrates a system 100 including a processing chamber 101, a gas source 160, and a flow controller 200 according to an embodiment of the present disclosure. The processing chamber 101 may be used for a process in which a corrosive plasma environment is provided. For example, the processing chamber 101 may be a chamber for a plasma etcher or plasma etch reactor, a plasma cleaner, etc. In alternative embodiments, other processing chambers may 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, etch chambers, and other types of processing chambers. In some embodiments, the processing chamber 101 may be any chamber used in an electronic device manufacturing system.

[0017] In one embodiment, the processing chamber 101 includes a chamber body 102 and a showerhead 130 that surrounds the interior space 106. The showerhead 130 may include a showerhead base and a showerhead gas distribution plate. Alternatively, the showerhead 130 may be replaced by a lid and nozzle in some embodiments, or by multiple pie-shaped showerhead sections and plasma generation units in other embodiments. The chamber body 102 may be fabricated from aluminum, stainless steel, or other suitable materials, such as titanium. The chamber body 102 generally includes a sidewall 108 and a bottom 110.

[0018] An outer liner 116 may be disposed adjacent the sidewall 108 to protect the chamber body 102. The outer liner 116 may be fabricated to include one or more apertures. In one embodiment, the outer liner 116 is fabricated from aluminum oxide.

[0019] An exhaust port 126 may be defined in the chamber body 102 and may connect the interior volume 106 to a pumping system 128. The pumping system 128 may include one or more pumps and a throttle valve utilized to evacuate the interior volume 106 of the processing chamber 101 and to regulate the pressure in the interior volume 106.

[0020] The gas source 160 may be connected to the processing chamber 101 to provide process gases and / or cleaning gases through the supply lines 112 and through the showerhead 130 to the interior space 106. The flow controller 200 may be connected to the gas source 160 and the processing chamber 101. The flow controller 200 may be used to measure and control the flow rate of gases from the gas source 160 to the interior space 106. An exemplary flow controller 200 is described in more detail below with respect to FIG. 2. In some embodiments, one or more gas panels 160 may be connected to the processing chamber 101 to provide gases to the interior space 106. In such embodiments, one or more flow controllers 200 may be connected to each of the gas source 160 and the processing chamber 101. In other embodiments, a single flow controller 200 may be connected to one or more gas panels 160. In some embodiments, the flow controller 200 may comprise a flow ratio controller for controlling the flow rate of gases to the processing chamber 101 (e.g., via one or more supply lines 112) or to other processing chambers.

[0021] The showerhead 130 may be supported on a sidewall 108 of the chamber body 102. The showerhead 130 (or lid) may open to allow access to the interior space 106 of the processing chamber 101 and may seal the processing chamber 101 while closed. A gas source 160 may be connected to the processing chamber 101 to provide process gases and / or cleaning gases to the interior space 106 via the showerhead 130 or the lid and nozzle (e.g., through apertures in the showerhead or lid and nozzle). The showerhead 130 may be used in processing chambers used for dielectric etching (etching dielectric materials). The showerhead 130 may include a gas distribution plate (GDP) and may have multiple gas delivery holes 132 (also referred to as channels) throughout the GDP. The showerhead 130 may be formed by a metal or alloy plate with protection by a multi-layer protective coating as described herein. The metal or alloy plate may be composed of aluminum, an aluminum alloy, or another metal or metal alloy. The showerhead 130 may be formed of a GDP bonded to an aluminum base or an anodized aluminum base. The GDP may be made of Si or SiC, or may be made of Y2O3, Al2O3, Y3Al5O 12 It may also be a ceramic such as (YAG).

[0022] For processing chambers used to etch conductive materials, a lid may be used rather than a showerhead. The lid may include a central nozzle that fits into a central hole in the lid. The lid may be a ceramic, such as Al2O3, Y2O3, YAG, or a ceramic compound including a solid solution of Y4Al2O9 and Y2O3-ZrO2. The nozzle may also be a ceramic, such as Y2O3, YAG, or a ceramic compound including a solid solution of Y4Al2O9 and Y2O3-ZrO2.

[0023] Examples of process gases that may be used to process a substrate in the process chamber 101 include halogen-containing gases such as C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, and SiF4, among others, and other gases such as O2 or N2O. The flow rate of any of these gases may be measured and regulated by the flow controller 200. A remote plasma may be formed from any of these and / or other process gases and then delivered to the chamber 101 via the supply line 112 through the flow controller 200. Thus, the remote plasma may be composed of C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, and SiF4, among others, and other gases such as O2 or N2O. Examples of carrier gases include N2, He, Ar, and other gases that are inert (eg, non-reactive) with respect to the process gas.

[0024] A substrate support assembly 148 is disposed in the interior space 106 of the processing chamber 101 below the showerhead 130. The substrate support assembly 148 holds the substrate 144 during processing. A ring (e.g., a single ring) can cover a portion of the electrostatic chuck 150 to protect the covered portion from exposure to plasma during processing. In one embodiment, the ring can be silicon or quartz. An inner liner can be covered on the outer periphery of the substrate support assembly 148. The inner liner can be a halogen-containing gas-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 can be manufactured from the same material as the outer liner 116.

[0025] In some embodiments, one or more sensor devices 170 may be disposed within the interior space 106. For example, the one or more sensor devices 170 may be positioned proximate (e.g., within 10 centimeters) to the showerhead 130. As another example, one or more sensor devices may be positioned proximate (e.g., within 10 centimeters) to the substrate 144 and may be used to monitor conditions near the reaction sites.

[0026] In one embodiment, the substrate support assembly 148 includes a pedestal 152 that supports the 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 insulation, and / or conduits to control the lateral temperature profile of the substrate support assembly 148. The electrostatic puck may further include a number of gas passages, such as grooves, mesas, and other surface features that may be formed on the top surface of the electrostatic puck. The gas passages may be fluidly coupled to a source of thermally conductive (or backside) gas, such as helium, through holes drilled in the electrostatic puck. During operation, a backside gas may be provided in the gas passages at a controlled pressure to enhance thermal conduction between the electrostatic puck and the supported substrate 144. The electrostatic chuck 150 may include at least one clamping electrode controlled by a chuck power supply.

[0027] 2 illustrates a flow controller 200 according to an embodiment of the present disclosure. The flow controller 200 may be configured to measure and control the mass flow rate of process gases and / or cleaning gases used in a manufacturing system and may therefore be considered a type of MFC. The flow controller 200 may be connected to the gas source 160 and the chamber 101 via gas flow channels 240. The gas flow channels may correspond to the supply lines 112 of FIG. 1. In some embodiments, the flow controller 200 may be incorporated into a flow ratio controller or a pulsed mass flow system.

[0028] 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 via a gas flow channel 240, through the flow regulator 210, and into the chamber 101. In other embodiments, the gas flow channel 240 may terminate somewhere other than 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., the ventilation system of a building or vehicle).

[0029] In some embodiments, the flow regulator 210 may comprise one or more flow regulating valves configured to restrict gas flow through the flow passage 242, each of which may be an actuatable valve, such as, for example, a solenoid valve or a piezoelectric valve. In some embodiments, the flow regulator includes other components in addition to the valves, such as flow or temperature sensing components. In some embodiments, the flow regulator 210 functions as an MFC, such as a thermal-based MFC, a pressure-based MFC, or a damping rate-based MFC.

[0030] In some embodiments in which the flow regulator 210 functions as a thermal-based MFC, the flow regulator 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 on-board processing device) a temperature delta that is proportional to the gas flow rate.

[0031] In some embodiments where the flow regulator 210 functions as a pressure-based MFC, the flow regulator 210 includes two pressure transducers and a temperature sensor upstream and downstream of the flow control valve. The flow rate of the gas is proportional to the product of the temperature and the difference between the squares of the upstream and downstream pressures.

[0032] In some embodiments where the flow regulator 210 functions as a damping rate-based MFC, the flow regulator 210 includes a valve to control the gas flow into a reservoir of a predetermined volume and a pressure sensor to measure the damping pressure in the reservoir. The gas flow rate is proportional to the rate of change of pressure.

[0033] In some embodiments, sensor device 220 is positioned downstream from flow regulator 210. Sensor device 220 may be part of flow regulator 210 (e.g., adjacent to a flow adjustment valve of flow regulator 210), near (e.g., within 10 centimeters) flow regulator 210, near (e.g., within 10 centimeters) an entrance to chamber 101 or showerhead 130, or within chamber 101 (which may be the same as or similar to sensor device 220, as shown in FIG. 1 for sensor device 170).

[0034] In some embodiments, the sensor device 220 comprises a MEMS device 222, which may be configured to generate one or more signals in response to a condition of the gas flow. For example, the MEMS device 222 may be configured to generate one or more signals indicative of a gas temperature or a gas flow rate. Exemplary MEMS devices are described in more detail below with respect to FIG. 3. In some embodiments, the sensor device 220 is attached to the gas flow channel 240 such that the MEMS device 222 is inserted directly into the flow path 242. The sensor device 220 is connected to the gas flow channel such that a seal is formed to prevent gas leakage. In some embodiments, the sensor device 220 includes a mounting plate to which the MEMS device 222 is secured via a seal (e.g., a metal seal).

[0035] In some embodiments, the processing device 230 includes a central processing unit (CPU), a microcontroller, a programmable logic controller (PLC), a system on a chip (SoC), a server computer, or other suitable type of computing device. The processing device 230 may be configured to execute programming instructions related to the operation of the flow regulator 210. The processing device 230 receives feedback signals from the sensor device 220 and, optionally, from the flow regulator 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 regulator 210 based on the received feedback signals. In some embodiments, the processing device 230 is configured for fast feedback processing and may include, for example, an EPM. In some embodiments, the processing device is configured to execute a process recipe, or one or more steps of a process recipe, for a manufacturing process using the chamber 101. For example, the recipe may specify gas flows at specific times, specific durations, and specific flow rates occurring for specific gases. As another example, the recipe may specify pulses of one or more gases.

[0036] 3A and 3B show top and side views, respectively, of an exemplary MEMS device 300 according to an embodiment of the present disclosure, which may be fabricated using semiconductor fabrication techniques well known to those skilled in the art. The MEMS device 300 may be the same as or similar to the MEMS device 222 described with respect to FIG. 2. The overall dimensions of the MEMS device 300 may be characterized by a length (L) of about 2 mm to about 10 mm, a width (W) of about 1 mm to about 5 mm, and a thickness (T) of about 0.1 mm to about 1 mm. The MEMS device 300 includes an elongated support structure 302 having a substantially planar shape. The elongated support structure 302 may 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. The elongated support structure 302 may have a tapered shape, which may improve its aerodynamic properties. The tapered region may further define a cavity 306 across which a freestanding sensing element, such as a nanowire 308, is suspended.

[0037] The electrodes 304 are shown disposed on a surface of the elongated support structure 302, extending from a flat end of the elongated support structure 302 to the nanowires 308. The electrodes 304 may be formed from one or more conductive metals. The electrodes may serve as electrical contacts to which one or more devices (e.g., processing device 230) may be operatively connected. In some embodiments, a portion of the electrodes 304 may be encapsulated or formed through the interior of the elongated support structure 302 to protect the electrodes 304 from corrosion.

[0038] FIG. 3C shows a close-up view of a nanowire 308 suspended between two electrodes 304. As used herein, the term "nanowire" refers to an electrical conductor having at least two dimensions less than one micrometer. In some embodiments, the nanowire 308 is formed from 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) on the elongated support structure 302 and selectively etching the elongated support structure 302, resulting in a free-standing nanowire 308 suspended across the 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 non-continuous structures may be utilized as long as they allow impedance measurements across the wire.

[0039] The nanowire 308 has a length (L) that is greater than its diameter or width / thickness. w ) whose dimensions are selected to allow the nanowires 308 to flex when exposed to both low and high velocity gas flows. In some embodiments, L W is less than 1 millimeter in length, for example, from about 1 micrometer to about 500 micrometers, or from about 10 micrometers to about 200 micrometers. Wis about 10 times to about 100,000 times larger than its diameter or width / thickness. In some embodiments, the nanowires 308 may have a circular or rectangular cross-section with a diameter or thickness / width of about 50 nanometers to about 500 nanometers. One skilled in the art will recognize that other dimensions may be utilized.

[0040] In some embodiments, 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 constant current anemometry (CCA), where a fixed current is passed through the nanowire 308, raising the temperature of the nanowire 308 and increasing its resistance. In operation, gas flow over the wire removes heat from the nanowire 308 by convection, and the resistance at constant current and constant gas velocity reaches a steady state. An increase or decrease in gas velocity results in a decrease or increase, respectively, in the resistance of the nanowire 308, allowing the measured voltage output to be correlated to the gas flow rate.

[0041] As another example, the MEMS device 300 may be configured for Elastic Filament Velocity Measurement (EFV). The gas velocity may be correlated to the strain of the nanowire 308 due to bending caused by the gas flow. In this operation, a small amount of current may be passed through the nanowire 308, resulting in negligible heating. During operation, the gas flow deflects the nanowire 308, creating internal stresses that change the resistance of the nanowire 308. The change in resistance may be correlated to the gas flow rate.

[0042] In some embodiments, the nanowire 308 can be combined with two or more nanowires with separate electrode pairs on the MEMS device 300, each of which can be used to perform CCA or EFV separately. In some embodiments, the two or more nanowires can be oriented in non-collinear directions.

[0043] 4A and 4B show top and side views, respectively, of an exemplary MEMS device 400 adapted for use in a flow control device (e.g., flow control device 200) according to an embodiment of the present disclosure. MEMS device 400 corresponds to a modified version of MEMS device 300 and includes metal band 410 and may also include non-conductive conformal coating 420 (as described below with respect to FIG. 4C). Elongated support structure 302 includes three regions. The first region is an interface region 402 for connecting MEMS device 400 to an external device, such as processing device 230. Electrodes 304 serve as electrical contacts for interacting with such external devices and may form a closed circuit during operation.

[0044] The second region is a connection region 404 that serves as a point at which the MEMS device 400 can be connected or attached to another structure, such as a mounting plate. The metal band 410 is positioned at the connection region that is disposed at a substantially central point of the elongated support structure 302. In some embodiments, the metal band 410 is positioned at another suitable point on the elongated support structure 302, so long as the metal band 410 does not overlap the cavity 306 or block the electrical connection to the electrode 304.

[0045] In some embodiments, the metal band 410 is formed from nickel, aluminum, another non-corroding metal, or an alloy thereof. In some embodiments, the metal band 410 can be deposited using techniques such as, for example, physical vapor deposition (PVD) or electroplating to deposit a continuous conformal layer surrounding a portion of the elongated support structure 302. A conformal layer covering multiple surfaces of the elongated support structure 302 is shown in FIGS. 4A and 4B. In FIG. 4A, a dotted line passing through the metal band 410 is shown to indicate that the electrode 304 is disposed below the metal band 410. In some embodiments, an insulating layer (e.g., SiO2) is deposited before the metal band 410 to separate the metal band 410 from the elongated support structure 302 and the electrode 304 to avoid shorting between the electrodes 304 during operation. In some embodiments, the thickness of the metal band 410 is between 50 micrometers and 500 micrometers. In some embodiments, the width of the metal band (i.e., the width measured along the longitudinal axis of the elongated support structure 302) is between 0.5 millimeters and 2 millimeters. In some embodiments, the metal band 410 does not form a continuous layer, but may be deposited, for example, as discrete islands of metal material.

[0046] 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, the connection region 404, and / or the 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 without covering the nanowires 380. In other embodiments, the conformal coating 420 covers only the portions of the MEMS device 400 that are exposed to the gas flow when the MEMS device 400 is inserted into a gas flow channel, as described below with respect to Figures 5A-5G.

[0047] In some embodiments, the conformal coating 420 covers at least a portion of the connection region 404 and / or the interface region 402. In some embodiments, the metal band 410 is disposed above the conformal coating 420, with the conformal coating 420 acting as an insulating layer between the metal band 410 and the electrode 304. In such embodiments, the conformal coating 420 is deposited prior to depositing the metal band 410.

[0048] 4C illustrates a cross-sectional view of an enlarged area of ​​the MEMS device 400, showing a conformal coating 420 on multiple surfaces of the elongated support structure 302. In some embodiments, the conformal coating 420 is deposited using a technique such as, for example, ALD, IAD, low pressure plasma spray (LPPS), chemical vapor deposition (CVD), plasma spray chemical vapor deposition (PS-CVD), sputtering, combinations thereof, or other techniques or modifications thereof suitable for forming a conformal coating. In some embodiments, the conformal coating 420 comprises a ceramic material that is resistant to corrosion by process gases or reactive species. For example, in some embodiments, the conformal coating is a ceramic material such as Y2O3, YZrO, Y 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, a rare earth ceramic selected from a Y2O3-ZrO2 solid solution, a ceramic comprising Y2Al4O9, and a Y2O3-ZrO2 solid solution, or a combination thereof. In some embodiments, the conformal coating 420 is substantially uniform, conformal, and non-porous.

[0049] As shown in FIG. 4C, in some embodiments, conformal coating 420 includes multiple layers 422A-422D deposited in succession. In some embodiments, there may be more or fewer layers than shown, and the number of layers may range from 1 to 100 layers, up to 500 layers, or more. For example, multiple atomically thin or near-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 conformal coating 420 may range from 10 nanometers to 300 nanometers.

[0050] 5A-5E illustrate the mounting of a MEMS device 400 to an exemplary mounting plate 500 according to an embodiment of the present disclosure. The mounting plate 500 may be in the form of a thin, flat metal sheet, although other suitable shapes such as circular, rectangular, etc. are envisioned. In some embodiments, the thickness of the mounting plate may range from 500 micrometers to 5 millimeters. The mounting plate 500 may be formed, for example, from 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 that is shaped to receive the MEMS device 400. In some embodiments, the slot 502 is sized so as not to physically contact the MEMS device 400 (or at least a portion of the MEMS device 400). 5C and 5D, the MEMS device 400 may be inserted into the slot 502 and then attached to the mounting surface 500B of the mounting plate 500, for example, by a seal 510 formed between the metal band 410 and the mounting plate 500. The seal 510 is an airtight seal that prevents gas leakage when the assembly of the mounting plate 500 and the MEMS device 400 is further connected to a gas flow channel, such as gas flow channel 520. In some embodiments, the seal 510 is a metal seal formed, for example, by brazing or soldering.

[0051] 5F shows a cross-sectional view of the mounting plate 500 and MEMS device 400 assembly connected to a gas flow channel 520, which may be similar to the configuration shown in FIG. 2 where the sensor device 220 is connected to the gas flow channel 240. In some embodiments, the gas flow channel 520 is a gas line, a branch channel of a gas line, or a separate component with an inlet and outlet that fits into the gas line. In some embodiments, the mounting plate is integrally formed with the gas flow channel 520. In some embodiments, the mounting plate 500 is mechanically connected to the gas flow channel.

[0052] When the mounting plate 500 is connected to the gas flow channels 520, the MEMS device 400 is inserted through the slots 522 in the gas flow channels 520 such that the nanowires 308 are disposed within the flow passages 530 of the gas flow channels 520 (orthogonal to the plane of the drawing). When the mounting plate 500 is in the form of a planar structure, a rubber O-ring 540 may be disposed between the gas-facing surface 500A of the mounting plate 500 and the gas flow channels 520 to form a seal, as shown. The leads 550 may be mechanically connected or soldered, for example, to the electrodes 304 of the MEMS device 400 to operably connect the MEMS device 400 to, for example, the processing device 230.

[0053] FIG. 6 illustrates a method 600 of adapting a sensor device for use in a flow control device according to an embodiment of the disclosure. At block 610, a sensor device is provided, such as sensor device 220 described above with respect to FIG. 2. In some embodiments, the sensor device includes a MEMS device, such as MEMS device 222 or 300 described with respect to FIGS. 2-5. In some embodiments, the sensor device includes an elongated support structure including an interface region (e.g., interface region 402), a sensor region (e.g., sensor region 406), and a connection region (e.g., connection region 404) positioned between the interface region and the sensor region. The sensor region may include a free-standing sensing element suspended in the sensor region, such as a nanowire (e.g., nanowire 308).

[0054] At block 620, a conformal coating (e.g., conformal coating 420) is deposited on the sensor device to at least partially cover 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 nanowires (e.g., nanowires 308). In other embodiments, the conformal coating covers the sensor area and does not cover or only minimally covers the nanowires.

[0055] 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 is deposited using one or more of Y2O3, YZrO, Y 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 solution, ceramics including Y2Al4O9, and Y2O3-ZrO2 solid solution, 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.

[0056] At block 630, a metal band (e.g., metal band 410) is deposited on the sensor device (i.e., on the MEMS device). In some embodiments, the metal band is deposited using one or both of PVD or electroplating. In some embodiments, the metal band forms a continuous conformal layer that surrounds a portion of the elongated support structure. In some embodiments, the metal band is deposited over a conformal coating. In other embodiments, the conformal coating is not present where the metal band is deposited or otherwise formed.

[0057] At 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 a metal band and the mounting plate, for example by brazing or soldering. In some embodiments, the sensor device is inserted into a gas flow channel and the mounting plate is mechanically connected to the gas flow channel (as shown in FIG. 5F).

[0058] For simplicity of explanation, the methods of the present disclosure are illustrated and described as a series of operations. However, operations according to the present disclosure may occur in various orders and / or simultaneously, and with other operations not shown or described herein. Moreover, not all of the illustrated operations may be required to implement a method in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that a method may alternatively be represented as a series of interrelated states, via a state diagram, or as events. Furthermore, it should be appreciated that the methods disclosed herein may be stored on an article of manufacture to facilitate the transfer and delivery of instructions for performing such 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.

[0059] FIG. 7 shows a schematic diagram of an exemplary form of a machine, computer system 700, within which a set of instructions (for causing the machine to perform any one or more of the methodologies described herein) may be executed. In alternative implementations, the machine may be connected (e.g., networked) to other machines in a LAN, WAN, intranet, extranet, or Internet. The machine may operate in the role of 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, cell phone, web appliance, server, network router, switch, or bridge, or any machine capable of executing a set of instructions (sequential or non-sequential) that specify operations to be performed by the machine. Furthermore, although only a single machine is shown, the term "machine" should also be understood to include any collection of machines that independently or jointly execute a set of instructions (or multiple sets of instructions) to perform any one or more of the methodologies described herein. Some or all of the components of the computer system 700 may be utilized by or represented by any of the electronic components described herein (e.g., the processing device 230, or any electronic components utilized in connection with the operation of the chamber 101 or the flow regulator 210).

[0060] The 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), etc.), 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.

[0061] Processor 702 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, etc. 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, etc. Processor 702 is configured to execute instructions 740 to perform the operations described herein.

[0062] Computer system 700 may further include a network interface device 708. Computer system 700 may also include a video display device 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).

[0063] The power device 718 may monitor the power level of a battery used to power the computer system 700 or one or more of its components. The power device 718 may provide one or more interfaces to provide an indication of the power level, a time window remaining until shutdown of the computer system 700 or one or more of its components, a power consumption rate, an indicator of whether the computer system is utilizing an external power source or a battery power source, and other power-related information. In some implementations, indications related to the power device 718 may be remotely accessible (e.g., accessible to a remote backup management module via a network connection). In some implementations, the battery utilized by the power device 718 may be an uninterruptible power supply (UPS) that is local or remote to the computer system 700. In such implementations, the power device 718 may provide information regarding the power level of the UPS.

[0064] The data storage device 720 may include a computer readable storage medium 724 (e.g., a non-transitory computer readable storage medium) on which is stored one or more sets of instructions 740 (e.g., software) implementing any one or more of the methods or functions described herein. These instructions 740 may reside, completely or at least partially, in the main memory 704 and / or the processor 702 while they are being executed by the computer system 700, with the main memory 704 and the processor 702 also constituting computer readable storage media. The instructions 740 may also be transmitted or received over a network 730 (e.g., network 14) via a network interface device 708. Although in one exemplary implementation, the computer readable storage medium 724 is shown as a single medium, it should be understood that the 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) that store one or more sets of instructions 740.

[0065] Many details have been set forth in the above description. However, it will be apparent to one of ordinary skill in the art having the benefit of this disclosure that the present disclosure may be practiced without these specific details. Although certain embodiments have been described herein, it should be understood that they are presented by way of example only and are not limiting. The breadth and scope of the present application should not be limited by any of the embodiments described herein, but should be defined only in accordance with the following and subsequent claims and their equivalents. Indeed, other various implementations and modifications of the present disclosure, in addition to those described herein, will be apparent to one of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other implementations and modifications are intended to be within the scope of the present disclosure.

[0066] Reference has been made to the accompanying drawings, which form a part of the description, in which specific embodiments are shown by way of example. While these disclosed embodiments have been described in sufficient detail to enable one skilled in the art to practice the embodiments, it should be understood that these examples 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 embodiments. For example, the blocks of the methods shown and described herein need not necessarily 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 those described. As another example, some blocks described as separate blocks herein may be combined in some other embodiments. Conversely, what may be described as a single block herein may be implemented in multiple blocks in some other embodiments. Furthermore, the conjunction "or" is intended herein in an inclusive sense where appropriate, unless otherwise indicated. 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", as well as "A, B, and C".

[0067] The word "example" or "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word "example" or "exemplary" is intended to present a concept in a concrete manner. When the term "about" or "approximately" is used herein, it is intended to mean that the nominal value presented is accurate to within ±10%.

[0068] In addition, the articles "a" and "an" as used in this specification and the appended claims should generally be construed to mean "one or more" unless otherwise specified or clear from the context to refer to the singular form. Throughout this specification, reference to "an embodiment," "one embodiment," "some embodiments," or "a particular embodiment" indicates that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Thus, the appearances of the phrases "an embodiment," "one embodiment," "some embodiments," or "a particular embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.

[0069] Some portions of the detailed descriptions may be presented in terms of algorithms and representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the methods used by those skilled in the data processing arts to most effectively convey the substance of their invention to others skilled in the art. An algorithm is here, and generally, conceived as a self-consistent sequence of steps leading to a desired result. The steps are steps requiring physical manipulations of quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transported, combined, compared, or otherwise manipulated. Sometimes, for convenience, and principally for reasons of common usage, these signals are referred to as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0070] It should be borne in mind, 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 indicated below, descriptions throughout this specification using terms such as "receiving," "retrieving," "transmitting," "computing," "generating," "processing," "reprocessing," "adding," "subtracting," "multiplying," "dividing," "optimizing," "calibrating," "detecting," "performing," "analyzing," "determining," "enabling," "identifying," "modifying," "transforming," "applying," "causing," "storing," "comparing," and the like, are understood to refer to operations and processes of a computer system or similar electronic computing device. This computer system or similar electronic computing device manipulates data represented as physical quantities (electrical quantities) in the computer system's registers and memory, and converts it to other data that is similarly represented as physical quantities in the computer system's memory or registers, or other storage, transmission, or display device for such information.

[0071] Moreover, while the disclosure has been described herein in the context of particular implementations in particular environments for particular purposes, those skilled in the art will recognize that its usefulness is not limited thereto, and that the disclosure may be advantageously implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the disclosure as described herein, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A sensor device, comprising: an elongated support structure including an interface region, a sensor region, and a connection region positioned between the interface region and the sensor region; an electrode disposed on the interface region; a sensing element suspended in the sensor region, the sensing element being electrically connected to the electrodes; a band-like conformal metal coating surrounding the connection area, the band-like conformal metal coating being sealed to the connection area of ​​the elongated support structure and being brazable such that the elongated support structure can be brazed to a mounting plate to form a metallic seal between the elongated support structure and the mounting plate; a non-conductive conformal coating comprising a plasma resistant ceramic material on at least a portion of the sensor area; and A sensor device comprising:

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

3. The sensor device of claim 1 or 2, wherein the non-conductive conformal coating has a thickness of about 10 nanometers to about 300 nanometers.

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

5. The sensor device of claim 4 , wherein the nanowires comprise platinum, and the nanowires are at least partially covered by the non-conductive conformal coating.

6. 6. The sensor device of claim 1, wherein the electrodes are formed on or in the connection regions, and the non-conductive conformal coating forms an insulating layer between the band-like conformal metal coating and the electrodes.

7. The mounting plate includes a gas-facing surface and a mounting surface opposite the gas-facing surface, the mounting plate having a slot formed therethrough; the elongated support structure is disposed within the slot such that the sensor region extends from the gas-facing surface and the connection region extends from the mounting surface; 7. The sensor device of claim 1, wherein the elongated support structure is fixed to the mounting plate at the connection region by the metal seal formed between the band-like conformal metal coating and the mounting surface of the mounting plate.

8. A flow control device, comprising: a gas flow channel defining a gas flow path; a flow regulating valve configured to regulate gas flow within the gas flow channel; A sensor device, comprising: an elongated support structure including a sensor region and a connection region; the sensor region includes a non-conductive conformal coating at least partially covering the sensor region and including a plasma resistant ceramic material, and a sensing element suspended in the sensor region within the gas flow path; the connection region includes a band-like conformal metal coating surrounding the connection region to seal the sensor device to the gas flow channel, the band-like conformal metal coating being sealed to the connection region and brazed to a mounting plate or an exterior region of the gas flow channel to form a metallic seal between the elongated support structure and the mounting plate or the exterior region of the gas flow channel. A sensor device; a processing device operatively connected to the flow control valve and the sensor device, the processing device configured to adjust the flow control valve based on a signal received from the sensor device; A flow control device comprising:

9. The flow controller of claim 8 , wherein the sensor device is a silicon-based micro-electro-mechanical system (MEMS) device.

10. The flow controller of claim 8 or 9, wherein the sensing element comprises a nanowire.

11. The flow control device of claim 8 , wherein the sensing element is at least partially covered by the non-conductive conformal coating comprising a plasma-resistant ceramic material.

12. The flow control device of claim 8 , wherein the elongated support structure is disposed within a slot formed in the mounting plate within the gas flow passage.

13. 13. The flow control device of claim 12, wherein the band-like conformal metal coating surrounds a portion of the elongated support structure extending from the slot in the gas flow passage, and the sensor device is secured to the gas flow passage by the mounting plate mechanically connected to the gas flow passage.

14. 13. The flow control device of claim 12, wherein the band-like conformal metal coating surrounds a portion of the elongated support structure extending from the slot of the gas flow channel, and the sensor device is secured to the gas flow path by an exterior region of the gas flow channel.

15. A method for enabling a sensor device to be attached to a flow control device, the method comprising: The sensor device is provided, the sensor device comprising: an elongated support structure including an interface region, a sensor region, and a connection region positioned between the interface region and the sensor region; and providing the sensor device including a sensing element suspended in the sensor area; depositing a conformal coating comprising a plasma resistant ceramic material over the sensor device to at least partially cover the sensor area; depositing a band-shaped conformal metal coating on the sensor device to surround the connection area, the band-shaped conformal metal coating being sealed to the connection area of ​​the elongated support structure and brazable such that the elongated support structure can be brazed to a mounting plate to form a metallic seal between the elongated support structure and the mounting plate; A method comprising:

16. The method of claim 15 , wherein the conformal coating is deposited using an atomic layer deposition process, the conformal coating comprising a non-conductive ceramic material.

17. 17. The method of claim 15 or 16, further comprising securing the sensor device to the mounting plate by forming the metallic seal between the band-like conformal metallic coating and the mounting plate.

18. inserting the sensor device into a gas flow channel; mechanically connecting said mounting plate to said gas flow channel; 20. The method of claim 17, further comprising:

19. 1. A method for controlling a flow rate in a gas flow channel, the method comprising:

15. A method comprising utilizing a flow control device according to any one of claims 8 to 14.

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