WO2002052363A1 - Pressure-based mass flow controller system - Google Patents

Pressure-based mass flow controller system Download PDF

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Publication number
WO2002052363A1
WO2002052363A1 PCT/US2001/024608 US0124608W WO02052363A1 WO 2002052363 A1 WO2002052363 A1 WO 2002052363A1 US 0124608 W US0124608 W US 0124608W WO 02052363 A1 WO02052363 A1 WO 02052363A1
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WO
WIPO (PCT)
Prior art keywords
flow
pressure
flow path
manifold
actual
Prior art date
Application number
PCT/US2001/024608
Other languages
French (fr)
Inventor
Paul Francis Grosshart
Original Assignee
Mks Instruments, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mks Instruments, Inc. filed Critical Mks Instruments, Inc.
Priority to GB0312001A priority Critical patent/GB2386704B/en
Priority to DE10196953T priority patent/DE10196953T1/en
Priority to KR10-2003-7008071A priority patent/KR20030074663A/en
Priority to JP2002553600A priority patent/JP2004517396A/en
Publication of WO2002052363A1 publication Critical patent/WO2002052363A1/en

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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00Control of flow
    • G05D7/06Control of flow characterised by the use of electric means
    • G05D7/0617Control of flow characterised by the use of electric means specially adapted for fluid materials
    • G05D7/0629Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
    • G05D7/0635Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means

Definitions

  • the present disclosure relates to the field of fluid flow measurement and control and, more particularly, to a pressure-based mass flow controller system for accurately controlling the delivery of low pressure vapors from a plurality of precursors.
  • Mass flow controllers are widely used in the industry to control the delivery of process reactants.
  • Thermal mass flow controllers operate on the principle that the rate of heat transfer from the walls of a flow channel to a fluid flowing in laminar flow within the channel is a function of the difference in temperatures of the fluid and the channel walls, the specific heat of the fluid, and the mass flow rate of the fluid.
  • the rate of mass flow of a fluid in the laminar flow regime
  • pressure-based MFCs establish a viscous flow condition by creating two pressure reservoirs along the flow path of a fluid, for example, by introducing a restriction in the diameter of the flow path.
  • the restriction may comprise an orifice or nozzle.
  • the fluid In the reservoir upstream of the flow restrictive aperture, the fluid has a pressure Pi and a density pi, which can be used to determine the flow with a known aperture under viscous chock flow conditions.
  • Distinct flow regimes of a flowing fluid are recognized and defined by different pressure profiles within the fluid.
  • Molecular flow occurs at fluid pressures of less than about 1 torr, and the flow rate of a fluid through a flow restrictive device, such as a nozzle, in the molecular flow regime is proportional to the pressure drop across the flow restrictive device.
  • Laminar flow occurs at fluid pressures of greater than about 10 torr, and the flow rate of a fluid through a flow restrictive device in the laminar flow regime is proportional to the difference of the squares of the upstream and downstream pressures.
  • the pressure-based mass flow controllers disclosed in, for example, U.S. Pat. No. 3,851,526 to Drexel and U.S. Pat. No. 5,445,035 to Delajoud operate on the assumption that the fluid flow remains laminar. This assumption of laminar fluid flow limits the utility of these pressure-based MFCs to laminar flow conditions and leads to inaccuracies when such MFCs are used to characterize non-laminar flows.
  • the relationship between mass flow of a fluid and the fluid pressure upstream of a flow restrictive device is linear above a certain critical pressure and nonlinear below that critical pressure. More specifically, when the upstream pressure Pi is at least twice as great as the downstream pressure P 2 (i.e., P ⁇ /P 2 ⁇ 2,) the flow is said to be choked, and the flow rate is a function only of P ⁇ P ⁇ and the cross-sectional area A of the flow restrictive aperture.
  • choked flow is typically established by maintaining the upstream fluid supply at a pressure that is always at least about twice that of the fluid in the downstream processing chamber, h a choked flow regime, as the pressure of the fluid in the upstream reservoir increases, the density and flow rate of the fluid also increase.
  • this relationship between flow rate and upstream pressure is linear so long as the upstream pressure remains at least twice that of the downstream pressure.
  • the upstream pressure is less than twice the downstream pressure (i.e., P ⁇ /P 2 ⁇ 2,)
  • the flow is said to be unchoked and the relationship between mass flow rate and downstream fluid pressure is nonlinear.
  • the controller includes a flow restrictive element in the fluid flow path, and the pressures of the fluid upstream and downstream of the flow restrictive element are measured. The ratio of the upstream and downstream fluid pressures is computed to determine whether the flow is choked or non-choked. The mass flow of the fluid is then computed by a CPU in accordance with a linear function of the upstream pressure, for choked flow, and in accordance with a nonlinear function of both the upstream and downstream pressures, for non-choked flow.
  • the present disclosure provides a pressure based mass flow controller for controlling the flow rate of a vapor from a source.
  • a controller can be used, for example, in the semiconductor manufacturing industry to precisely deliver a process vapor to a process chamber for making a semiconductor wafer.
  • the disclosed flow controller has a simplified, novel design, that allows the disclosed flow controller to be easily and inexpensively incorporated in a system including a plurality of mass flow controllers and a plurality of fluid sources.
  • the flow controller includes a flow path fortonnection to a fluid source, a flow restrictor dividing the flow path into an upstream reservoir and a downstream reservoir, an upstream pressure measurement device connected to the upstream reservoir, and a flow valve connected to the flow path before the upstream reservoir.
  • the flow controller also includes a control device programmed to receive a predetermined desired flow rate, receive an indication of upstream pressure from the upstream pressure measurement device, and receive an indication of downstream pressure from a remote downstream pressure measurement device connected to the downstream reservoir.
  • the control device is also programmed to determine an actual mass flow rate of vapor through the flow path during choked flow conditions in accordance with a linear function of the upstream pressure, and determine the actual mass flow rate of the vapor through the flow path during non-choked flow conditions in accordance with a nonlinear function of the upstream pressure and the downstream pressure.
  • the present disclosure provides a system for controlling the flow rates of fluids derived from a plurality of sources.
  • the system includes a mass flow controller as described above for each of the plurality of sources.
  • the system further includes a manifold connecting the downstream reservoirs of the mass flow controllers, and a single downstream pressure measurement device connected to the manifold for providing an indication of the downstream pressure to the control devices of the flow controllers.
  • the system includes a flow path for connection to each of the plurality of vapor sources, flow restrictors dividing each of the flow paths into an upstream reservoir and a downstream reservoir, and upstream pressure measurement devices connected to each of the upstream reservoirs.
  • a manifold connects the downstream reservoirs of the mass flow controllers, and a downstream pressure measurement device connected to the manifold.
  • the system also includes a control device programmed to, for each flow path, receive an indication of upstream pressure from the upstream pressure measurement device of the flow path, and receive an indication of downstream pressure from the downstream pressure measurement device.
  • the control device determines an actual mass flow rate of vapor through the flow path in accordance with a linear function of the upstream pressure during choked flow conditions, and determines the actual mass flow rate of the vapor through the flow path in accordance with a nonlinear function of the upstream pressure and the downstream pressure during unchoked flow conditions.
  • FIG. 1 is a graph illustrating the relationship of mass flow and the pressure drop of a fluid across a flow restrictive element defining an upstream and downstream reservoir. The graph illustrates both choked and non-choked flow conditions;
  • FIG. 2 is a simplified schematic diagram of a pressure-based mass flow controller according to the present disclosure
  • FIG. 3 is a simplified schematic diagram of a system according to the present disclosure, including a plurality of the pressure-based mass flow controllers of FIG. 2;
  • FIG. 4 is a simplified schematic diagram of another pressure-based mass flow controller system according to the present disclosure.
  • the present disclosure provides a pressure-based mass flow controller (MFC) 10 for controlling the flow rate of a vapor from a source.
  • MFC mass flow controller
  • Such a controller 10 can be used, for example, in the semiconductor manufacturing industry to precisely deliver a process vapor to a process chamber for making a semiconductor wafer.
  • the disclosed MFC 10 can be used with a low vapor pressure source, and has a simplified, novel design, that allows the disclosed flow controller 10 to be easily and inexpensively incorporated in a system including a plurality of mass flow controllers and a plurality of vapor sources.
  • the MFC 10 includes a flow path 12 for connection to a vapor source, a flow restrictor 14 dividing the flow path into an upstream reservoir 16 and a downstream reservoir 18, an upstream pressure measurement device 20 connected to the upstream reservoir, and a flow valve 22 connected to the flow path before the upstream reservoir.
  • the MFC 10 also includes a control device 24 programmed to receive a predetermined desired flow rate, receive an indication of upstream pressure from the upstream pressure measurement device 20 (as indicated by control circuitry 26), and receive an indication of downstream pressure from a remote downstream pressure measurement device (not shown) connected to the downstream reservoir 18.
  • the control device 24 is also programmed to determine an actual mass flow rate of vapor through the flow path 12 during choked flow conditions in accordance with a linear function of the upstream pressure, and determine the actual mass flow rate of the vapor through the flow path 12 during non- choked flow conditions in accordance with a nonlinear function of the upstream pressure and the downstream pressure.
  • the control device 24 is programmed to instruct the flow valve 22 (as indicated by control circuitry 28) to increase flow if the actual flow rate is less than the desired flow rate, and to decrease flow if the actual flow rate is greater than the desired flow rate.
  • the size of an aperture in the flow restrictor 14 is initially determined by the fluid pressures at the inlet and the outlet of the MFC 10, and clearly can be proportioned to maximize performance and control range of fluid flows.
  • control device 24 it is meant herein a device or mechanism used to regulate or guide the operation of the MFC 10.
  • the control device 24 preferably comprises a computer processing unit (CPU) including a processor and memory.
  • CPU computer processing unit
  • the control device 24 operates in a feedback loop to maintain the desired flow at all times.
  • Equations performed by the control device 24 for computing the mass flow rate from the measured reservoir pressures during both choked flow and non-choked flow conditions are disclosed in U.S. Patent No. 5,868,159, which is assigned to the assignee of the present disclosure and incorporated herein by reference.
  • the control device 24 stores user input parameters necessary for carrying out the calculations.
  • the cross-sectional diameter of the aperture in the flow restrictor 14 is typically input by a user and, indirectly, the discharge coefficient of the flow restrictor.
  • Values of the molecular weight, the universal gas constant, and the specific heat ration for several gases may be input or previously stored in the control device.
  • the parameters as well as a desired flow rate can be entered into the control device 24 through a user input device (not shown), such as a keyboard and monitor for example, via an analog set point.
  • the determination by the control device 24 of the mass flow rate also forms the basis of a feedback loop for adjusting the flow valve 22 in response to changes in fluid pressure within the upstream reservoir and/or the downstream reservoir to ensure that the actual flow rate is the same as the input desired flow rate.
  • Information on flow rate as a function of the flow valve control current is preferably stored in the control device 24 in order to quicken the response time of the MFC 10.
  • the pressure measurement device 20 can be any type of pressure transducer capable of measuring fluid pressures within the range of interest.
  • the pressure measurement device can include an absolute pressure transducer 20.
  • Preferred pressure measurement devices comprise Baratron ® capacitance manometers available from MKS Instruments, Inc. of Andover, MA (www.mksinst.com).
  • the flow, or control, valve 22 may be any kind of valve for controlling the flow of fluid through the flow path 12 in response to a control signal provided from the control device 24.
  • the flow valve 22 and the control device 24 accommodate all flow rates from a complete shut off position (providing zero flow) to a complete open position (providing maximum flow), including flow rates required for choked as well as non-choked flow, although under certain applications it may be desirable to design the controller for only one flow regime.
  • the specific characteristics of the flow valve 22 will depend on the expected delivery pressure range of the precursor material and the dimensions of the flow path 12 and the flow restrictor 14, and can be, for example, as a solenoid valve, a throttle valve or a flapper valve.
  • a preferred valve is a proportioning solenoid control valve 22.
  • the flow path 12 is maintained at a constant, desired temperature preferably by surrounding the flow path with temperature control means, including thermal insulating means, a heater 30, and one or more temperature sensors 32 for sensing the temperature(s) along the flow path and for operating the heater in a feedback arrangement so as to maintain the temperature of the flow path at a predetermined fixed temperature.
  • the control device 24 employs feedback control loops for accurately controlling the temperature of the fluid (and for maintaining the temperature of the flow path 12 at a desired temperature) in response to changes in fluid flow. Signals sent from the temperature sensors 32 to the control device (as indicated by control circuitry 34) operate to controllably adjust the heater 30 (as indicated by control circuitry 36) and, thus, the temperature of the vapor in the flow path 12.
  • a predetermined temperature set point or range can be programmed into the control device 24 to ensure that the fluid is maintained at the desired temperature or range.
  • the pressure-based MFC 10 of the present disclosure can be used to deliver gaseous reactants from liquid and non-dissolved solid precursors characterized by a wide range of vapor pressures at the delivery temperatures.
  • the pressure-based MFC 10 of the present disclosure may be used to monitor and control the delivery of fluids to a process, or reaction, chamber in a variety of industrial applications, including the manufacture of semiconductor devices using precursor materials having relatively low vapor pressures.
  • precursor materials include liquid precursors having low vapor pressures and solid precursors which sublime, i.e., enter the gaseous state directly from the solid state.
  • the solid precursor materials may be melted at an appropriate temperature and the mass flow of the gaseous reactants derived therefrom may be determined using the MFC 10 of the present disclosure, without the use of a solvent.
  • the pressure-based MFC 10 of the present disclosure is particularly suitable for use in systems that require delivery of gaseous reactants of high purity to a processing chamber.
  • the pressure-based MFC 10 of the present disclosure effectively and more reliably models the relationship between upstream fluid pressure and mass flow rate, since it is capable of determining and controlling mass flow rate with high accuracy and fast response time over a wide range of flow rates in both the choked and non-choked flow regimes for a wide variety of fluids.
  • the pressure-based MFC 10 of the present disclosure includes the versatility of the unit.
  • a single MFC 10 according to the disclosure can be used in applications in which, formerly, several MFCs, each calibrated for a particular gas, temperature, pressure and/or a particular flow rate range, were required.
  • the MFC 10 can be used to control the flow rate of a vapor derived from a precursor characterized by a vapor pressure ranging as low as 2 torr or lower, to at least 760 torr or higher, at temperatures of up to at least 250°C or higher.
  • the pressure transducer 20, heating element 30, CPU 24, valve 22 and controlling circuitry which comprise the MFC 10 are provided in a relatively compact, integral unit.
  • the calibration and computations are performed in-line by the CPU 24.
  • the feedback control loops are digitally controlled for improved accuracy and response time; however, both analog and digital operation are permitted.
  • the on-board calibration feature of the present disclosure provides additional accuracy and reliability, as calibration of the MFC 10 can be done at multiple increments of full scale readings instead of merely at 0 and 100 percent full scale.
  • calibration of the individual components, namely, the pressure transducer 20, is not required.
  • the system 50 of FIG. 3 includes a mass flow controller 10 according to FIG. 2 for each of the plurality of sources.
  • the system 50 further includes a manifold 52 connecting the downstream reservoirs 18 of the MFCs 10, and a downstream pressure measurement device 54 connected to the manifold 52 for providing an indication of the downstream pressure to the control devices 24 of the MFCs (as indicated by confrol circuitry 56).
  • the pressure measurement device 54 can comprise an absolute pressure transducer, and preferably comprises a Baratron ® capacitance manometer.
  • the system 50 also includes inlet valves 58 for connecting the upstream reservoirs 16 of the MFCs 10 to their respective sources of vapor, and outlet valves 60 connecting the downstream reservoirs 18 of the MFCs to the manifold 52, whereby at least one of the mass flow controllers 10 can be made to communicate with the manifold 52.
  • a valve 62 is also provided for connecting the manifold 52 to the process chamber.
  • the system 50 can additionally include temperature measurement devices 64 connected to the manifold 52, a heater 66 for heating the manifold, and a control device 68 (i.e., CPU) for maintaining the manifold at a constant, desired temperature, similar to the temperature control system of each MFC 10.
  • the control device 68 is programmed to receive a desired vapor temperature from a user input device, and receive an indication of actual vapor temperature within the manifold 52 from the temperature measurement devices 64 (as indicated by control circuitry 70).
  • the control device 68 then instructs the heater 66 (as indicated by control circuitry 72) to increase heat to the manifold 52 if the actual vapor temperature within the manifold is less than the desired vapor temperature, and instruct the heater to decrease heat to the manifold if the actual vapor temperature within the manifold is greater than the desired vapor temperature.
  • a single temperature control system can be provided for the mass flow controller system 50 in place of the separate systems for each MFC 10 and the system for the manifold 52.
  • FIG. 4 another mass flow controller system 80 according to the present disclosure is shown.
  • the system 80 of FIG. 4 is similar to the system 50 of FIG. 3, and elements that are the same have the same reference numerals.
  • the system 80 includes a mass flow controller 110 for each of the plurality of vapor sources.
  • the MFCs 110 of FIG. 4 are similar to the MFCs 10 of FIG. 3 except that the MFCs 110 are not provided with their own CPUs. Instead the system 80 is provided with a single control device (i.e., CPU) 82 connected to each of the MFCs 110 (as indicated by control circuitry 84) and connected to downstream pressure measurement device 54 (as indicated by control circuitry 86) of the manifold 52.
  • the control device 82 controls the flow valves 22 of each MFC 110 based upon upstream and downstream pressure readings provided by the upstream pressure measurement devices 20 of the MFCs 110 and the downstream pressure measurement device 54 of the manifold 52.
  • the control device 82 is also preferably connected to the temperature measurement devices 64 and the heater 66 (as indicated by confrol circuitry 88, 90) of the manifold 52, for maintaining the manifold at a constant, desired temperature.

Abstract

A pressure based mass flow controller (10)that can be used, for example, in semiconductor manufacturing for precisely delivering a process gas to a process chamber. The controller can be used with a low pressure source, and has a simplified, novel design, that allows the controller (10) to be easily and inexpensively incorporated in a system including a plurality of such controllers and a plurality of gas sources. The controller includes a flow path (12) for connection to a fluid source, a flow restrictor (149) dividing the flow path into an upstream reservoir (16) and a downstream reservoir (18), an upstream pressure measurement device (20) connected to the upstream reservoir, and a flow valve (22) connected to the flow path. The controller also includes a control device (24) programmed to receive a desired flow rate, an indication of upstream pressure for the upstream pressure measurement device, an indication of downstream pressure from a remote downstream pressure measurement device connected to the downstream reservoir (18). The control device (24) then determines an actual mass flow rate during choked flow conditions in accordance with a linear function of the upstream pressure, and during non-choked flow conditions in accordance with a nonlinear function of the upstream pressure and the downstream pressure. The control device (24) is also programmed to instruct the flow rate valve to increase flow if the actual flow rate is less than the desired flow rate, and to decrease flow if the actual flow rate is greater than the desired flow rate.

Description

PRESSURE-BASED MASS FLOW CONTROLLER SYSTEM
Field of Disclosure
The present disclosure relates to the field of fluid flow measurement and control and, more particularly, to a pressure-based mass flow controller system for accurately controlling the delivery of low pressure vapors from a plurality of precursors.
Background of Disclosure
In the semiconductor manufacturing industry, it is necessary to achieve precise control of the quantity, temperature and pressure of one or more reactant materials which are delivered in the gaseous state to a reaction chamber. Some process reactants, such as nitrogen gas, are relatively easy to deliver in a controlled manner at the temperatures and pressures required for the reaction to occur. Other reactants, however, may be highly corrosive, toxic, pyrophoric, or unstable at the temperatures and/or pressures at which delivery to the reaction chamber is required. Such characteristics of the reactants make their accurate and controlled delivery to a reaction chamber extremely difficult to achieve.
Mass flow controllers (hereinafter, "MFCs") are widely used in the industry to control the delivery of process reactants. Two broad categories of MFCs, thermal and pressure-based, have been developed to handle the diverse delivery requirements of a wide variety of process reactants. Thermal mass flow controllers operate on the principle that the rate of heat transfer from the walls of a flow channel to a fluid flowing in laminar flow within the channel is a function of the difference in temperatures of the fluid and the channel walls, the specific heat of the fluid, and the mass flow rate of the fluid. Thus, the rate of mass flow of a fluid (in the laminar flow regime) can be determined if the properties of the fluid and the temperatures of the fluid and tube are known.
On the other hand, pressure-based MFCs establish a viscous flow condition by creating two pressure reservoirs along the flow path of a fluid, for example, by introducing a restriction in the diameter of the flow path. The restriction may comprise an orifice or nozzle. In the reservoir upstream of the flow restrictive aperture, the fluid has a pressure Pi and a density pi, which can be used to determine the flow with a known aperture under viscous chock flow conditions.
Distinct flow regimes of a flowing fluid are recognized and defined by different pressure profiles within the fluid. Molecular flow occurs at fluid pressures of less than about 1 torr, and the flow rate of a fluid through a flow restrictive device, such as a nozzle, in the molecular flow regime is proportional to the pressure drop across the flow restrictive device. Laminar flow occurs at fluid pressures of greater than about 10 torr, and the flow rate of a fluid through a flow restrictive device in the laminar flow regime is proportional to the difference of the squares of the upstream and downstream pressures.
The pressure-based mass flow controllers disclosed in, for example, U.S. Pat. No. 3,851,526 to Drexel and U.S. Pat. No. 5,445,035 to Delajoud operate on the assumption that the fluid flow remains laminar. This assumption of laminar fluid flow limits the utility of these pressure-based MFCs to laminar flow conditions and leads to inaccuracies when such MFCs are used to characterize non-laminar flows.
As can be seen in the graph of FIG. 1, the relationship between mass flow of a fluid and the fluid pressure upstream of a flow restrictive device is linear above a certain critical pressure and nonlinear below that critical pressure. More specifically, when the upstream pressure Pi is at least twice as great as the downstream pressure P2 (i.e., Pι/P2 ≥ 2,) the flow is said to be choked, and the flow rate is a function only of PχPι and the cross-sectional area A of the flow restrictive aperture. In general, choked flow is typically established by maintaining the upstream fluid supply at a pressure that is always at least about twice that of the fluid in the downstream processing chamber, h a choked flow regime, as the pressure of the fluid in the upstream reservoir increases, the density and flow rate of the fluid also increase.
As shown in the graph of FIG. 1, this relationship between flow rate and upstream pressure is linear so long as the upstream pressure remains at least twice that of the downstream pressure. However, when the upstream pressure is less than twice the downstream pressure (i.e., Pι/P2 < 2,), the flow is said to be unchoked and the relationship between mass flow rate and downstream fluid pressure is nonlinear.
No special provision was made to permit a pressure-based MFC, calibrated for choked flow operation, to operate in the non-linear, non-choked flow region. In the Model 1150 mass flow controller, for example, only the upstream fluid pressure is measured. In such choked-flow devices, any measurements of flow rate are assumed to be linearly related to the upstream pressure, as seen by the dotted line A in FIG. 1, even though the upstream pressure is actually less than twice the downstream pressure. In the non-choked flow regime, i.e., when the upstream pressure is less than twice the downstream pressure, the flow rate of the fluid varies as a function of the downstream fluid pressure and is independent of the upstream fluid pressure.
In a more recent pressure-based mass flow controller, exemplified by the Model 1153 mass flow controller manufactured and sold by the assignee of the present disclosure, the necessity for assuming the flow rate is linearly related to the upstream pressure, even in the non-choked flow regime, is avoided. The controller includes a flow restrictive element in the fluid flow path, and the pressures of the fluid upstream and downstream of the flow restrictive element are measured. The ratio of the upstream and downstream fluid pressures is computed to determine whether the flow is choked or non-choked. The mass flow of the fluid is then computed by a CPU in accordance with a linear function of the upstream pressure, for choked flow, and in accordance with a nonlinear function of both the upstream and downstream pressures, for non-choked flow.
What is desired now is mass flow controller system which is suitable for use in the delivery of many types of fluids over a relatively wide range of operating temperatures, pressures and flow rates, without the need for individual measurement of downstream pressure.
Summary of Disclosure
The present disclosure provides a pressure based mass flow controller for controlling the flow rate of a vapor from a source. Such a controller can be used, for example, in the semiconductor manufacturing industry to precisely deliver a process vapor to a process chamber for making a semiconductor wafer. The disclosed flow controller has a simplified, novel design, that allows the disclosed flow controller to be easily and inexpensively incorporated in a system including a plurality of mass flow controllers and a plurality of fluid sources.
The flow controller includes a flow path fortonnection to a fluid source, a flow restrictor dividing the flow path into an upstream reservoir and a downstream reservoir, an upstream pressure measurement device connected to the upstream reservoir, and a flow valve connected to the flow path before the upstream reservoir.
The flow controller also includes a control device programmed to receive a predetermined desired flow rate, receive an indication of upstream pressure from the upstream pressure measurement device, and receive an indication of downstream pressure from a remote downstream pressure measurement device connected to the downstream reservoir. The control device is also programmed to determine an actual mass flow rate of vapor through the flow path during choked flow conditions in accordance with a linear function of the upstream pressure, and determine the actual mass flow rate of the vapor through the flow path during non-choked flow conditions in accordance with a nonlinear function of the upstream pressure and the downstream pressure.
The present disclosure provides a system for controlling the flow rates of fluids derived from a plurality of sources. The system includes a mass flow controller as described above for each of the plurality of sources. The system further includes a manifold connecting the downstream reservoirs of the mass flow controllers, and a single downstream pressure measurement device connected to the manifold for providing an indication of the downstream pressure to the control devices of the flow controllers.
Another system for controlling the flow rates of vapors derived from a plurality of sources is also provided. The system includes a flow path for connection to each of the plurality of vapor sources, flow restrictors dividing each of the flow paths into an upstream reservoir and a downstream reservoir, and upstream pressure measurement devices connected to each of the upstream reservoirs. A manifold connects the downstream reservoirs of the mass flow controllers, and a downstream pressure measurement device connected to the manifold.
The system also includes a control device programmed to, for each flow path, receive an indication of upstream pressure from the upstream pressure measurement device of the flow path, and receive an indication of downstream pressure from the downstream pressure measurement device. The control device then determines an actual mass flow rate of vapor through the flow path in accordance with a linear function of the upstream pressure during choked flow conditions, and determines the actual mass flow rate of the vapor through the flow path in accordance with a nonlinear function of the upstream pressure and the downstream pressure during unchoked flow conditions.
Brief Description of Drawings
The foregoing and other features and advantages of this disclosure will be better understood from the detailed description and the drawings, in which: FIG. 1 is a graph illustrating the relationship of mass flow and the pressure drop of a fluid across a flow restrictive element defining an upstream and downstream reservoir. The graph illustrates both choked and non-choked flow conditions;
FIG. 2 is a simplified schematic diagram of a pressure-based mass flow controller according to the present disclosure;
FIG. 3 is a simplified schematic diagram of a system according to the present disclosure, including a plurality of the pressure-based mass flow controllers of FIG. 2; and
FIG. 4 is a simplified schematic diagram of another pressure-based mass flow controller system according to the present disclosure.
Detailed Description of Disclosure
Referring to FIG. 2, the present disclosure provides a pressure-based mass flow controller (MFC) 10 for controlling the flow rate of a vapor from a source. Such a controller 10 can be used, for example, in the semiconductor manufacturing industry to precisely deliver a process vapor to a process chamber for making a semiconductor wafer. The disclosed MFC 10 can be used with a low vapor pressure source, and has a simplified, novel design, that allows the disclosed flow controller 10 to be easily and inexpensively incorporated in a system including a plurality of mass flow controllers and a plurality of vapor sources.
The MFC 10 includes a flow path 12 for connection to a vapor source, a flow restrictor 14 dividing the flow path into an upstream reservoir 16 and a downstream reservoir 18, an upstream pressure measurement device 20 connected to the upstream reservoir, and a flow valve 22 connected to the flow path before the upstream reservoir.
The MFC 10 also includes a control device 24 programmed to receive a predetermined desired flow rate, receive an indication of upstream pressure from the upstream pressure measurement device 20 (as indicated by control circuitry 26), and receive an indication of downstream pressure from a remote downstream pressure measurement device (not shown) connected to the downstream reservoir 18. The control device 24 is also programmed to determine an actual mass flow rate of vapor through the flow path 12 during choked flow conditions in accordance with a linear function of the upstream pressure, and determine the actual mass flow rate of the vapor through the flow path 12 during non- choked flow conditions in accordance with a nonlinear function of the upstream pressure and the downstream pressure.
The control device 24 is programmed to instruct the flow valve 22 (as indicated by control circuitry 28) to increase flow if the actual flow rate is less than the desired flow rate, and to decrease flow if the actual flow rate is greater than the desired flow rate. The size of an aperture in the flow restrictor 14 is initially determined by the fluid pressures at the inlet and the outlet of the MFC 10, and clearly can be proportioned to maximize performance and control range of fluid flows.
By "control device" 24 it is meant herein a device or mechanism used to regulate or guide the operation of the MFC 10. The control device 24 preferably comprises a computer processing unit (CPU) including a processor and memory. The control device 24 operates in a feedback loop to maintain the desired flow at all times.
Equations performed by the control device 24 for computing the mass flow rate from the measured reservoir pressures during both choked flow and non-choked flow conditions are disclosed in U.S. Patent No. 5,868,159, which is assigned to the assignee of the present disclosure and incorporated herein by reference. In general, the control device 24 stores user input parameters necessary for carrying out the calculations. For example, the cross-sectional diameter of the aperture in the flow restrictor 14 is typically input by a user and, indirectly, the discharge coefficient of the flow restrictor. Values of the molecular weight, the universal gas constant, and the specific heat ration for several gases may be input or previously stored in the control device. The parameters as well as a desired flow rate can be entered into the control device 24 through a user input device (not shown), such as a keyboard and monitor for example, via an analog set point.
The determination by the control device 24 of the mass flow rate also forms the basis of a feedback loop for adjusting the flow valve 22 in response to changes in fluid pressure within the upstream reservoir and/or the downstream reservoir to ensure that the actual flow rate is the same as the input desired flow rate. Information on flow rate as a function of the flow valve control current is preferably stored in the control device 24 in order to quicken the response time of the MFC 10.
The pressure measurement device 20 can be any type of pressure transducer capable of measuring fluid pressures within the range of interest. For example, the pressure measurement device can include an absolute pressure transducer 20. Preferred pressure measurement devices comprise Baratron® capacitance manometers available from MKS Instruments, Inc. of Andover, MA (www.mksinst.com).
The flow, or control, valve 22 may be any kind of valve for controlling the flow of fluid through the flow path 12 in response to a control signal provided from the control device 24. Preferably, the flow valve 22 and the control device 24 accommodate all flow rates from a complete shut off position (providing zero flow) to a complete open position (providing maximum flow), including flow rates required for choked as well as non-choked flow, although under certain applications it may be desirable to design the controller for only one flow regime. The specific characteristics of the flow valve 22 will depend on the expected delivery pressure range of the precursor material and the dimensions of the flow path 12 and the flow restrictor 14, and can be, for example, as a solenoid valve, a throttle valve or a flapper valve. A preferred valve is a proportioning solenoid control valve 22.
The flow path 12 is maintained at a constant, desired temperature preferably by surrounding the flow path with temperature control means, including thermal insulating means, a heater 30, and one or more temperature sensors 32 for sensing the temperature(s) along the flow path and for operating the heater in a feedback arrangement so as to maintain the temperature of the flow path at a predetermined fixed temperature. Specifically, the control device 24 employs feedback control loops for accurately controlling the temperature of the fluid (and for maintaining the temperature of the flow path 12 at a desired temperature) in response to changes in fluid flow. Signals sent from the temperature sensors 32 to the control device (as indicated by control circuitry 34) operate to controllably adjust the heater 30 (as indicated by control circuitry 36) and, thus, the temperature of the vapor in the flow path 12. A predetermined temperature set point or range can be programmed into the control device 24 to ensure that the fluid is maintained at the desired temperature or range.
By providing accurate flow rate measurement for non-choked flow conditions, the pressure-based MFC 10 of the present disclosure can be used to deliver gaseous reactants from liquid and non-dissolved solid precursors characterized by a wide range of vapor pressures at the delivery temperatures.
Thus, the pressure-based MFC 10 of the present disclosure may be used to monitor and control the delivery of fluids to a process, or reaction, chamber in a variety of industrial applications, including the manufacture of semiconductor devices using precursor materials having relatively low vapor pressures. Such precursor materials include liquid precursors having low vapor pressures and solid precursors which sublime, i.e., enter the gaseous state directly from the solid state. Alternatively, the solid precursor materials may be melted at an appropriate temperature and the mass flow of the gaseous reactants derived therefrom may be determined using the MFC 10 of the present disclosure, without the use of a solvent.
As a consequence, the pressure-based MFC 10 of the present disclosure is particularly suitable for use in systems that require delivery of gaseous reactants of high purity to a processing chamber. In addition, the pressure-based MFC 10 of the present disclosure effectively and more reliably models the relationship between upstream fluid pressure and mass flow rate, since it is capable of determining and controlling mass flow rate with high accuracy and fast response time over a wide range of flow rates in both the choked and non-choked flow regimes for a wide variety of fluids.
Other advantages of the pressure-based MFC 10 of the present disclosure include the versatility of the unit. A single MFC 10 according to the disclosure can be used in applications in which, formerly, several MFCs, each calibrated for a particular gas, temperature, pressure and/or a particular flow rate range, were required. For example, the MFC 10 can be used to control the flow rate of a vapor derived from a precursor characterized by a vapor pressure ranging as low as 2 torr or lower, to at least 760 torr or higher, at temperatures of up to at least 250°C or higher. In addition, the pressure transducer 20, heating element 30, CPU 24, valve 22 and controlling circuitry which comprise the MFC 10 are provided in a relatively compact, integral unit. Furthermore, the calibration and computations are performed in-line by the CPU 24. The feedback control loops are digitally controlled for improved accuracy and response time; however, both analog and digital operation are permitted. The on-board calibration feature of the present disclosure provides additional accuracy and reliability, as calibration of the MFC 10 can be done at multiple increments of full scale readings instead of merely at 0 and 100 percent full scale. In addition, calibration of the individual components, namely, the pressure transducer 20, is not required.
Referring now to FIG. 3, a mass flow controller system 50 according to the present disclosure for controlling the flow rates of vapors derived from a plurality of sources is shown. The system 50 of FIG. 3 includes a mass flow controller 10 according to FIG. 2 for each of the plurality of sources. The system 50 further includes a manifold 52 connecting the downstream reservoirs 18 of the MFCs 10, and a downstream pressure measurement device 54 connected to the manifold 52 for providing an indication of the downstream pressure to the control devices 24 of the MFCs (as indicated by confrol circuitry 56). The pressure measurement device 54 can comprise an absolute pressure transducer, and preferably comprises a Baratron® capacitance manometer.
By providing a single downstream pressure measurement device 54 for use by all of the MFCs 10, as opposed to providing each MFC with its own downstream pressure measurement device, among other benefits and advantages, a simpler and less expense mass flow control system 50 is provided.
As shown in FIG. 3, the system 50 also includes inlet valves 58 for connecting the upstream reservoirs 16 of the MFCs 10 to their respective sources of vapor, and outlet valves 60 connecting the downstream reservoirs 18 of the MFCs to the manifold 52, whereby at least one of the mass flow controllers 10 can be made to communicate with the manifold 52. A valve 62 is also provided for connecting the manifold 52 to the process chamber.
The system 50 can additionally include temperature measurement devices 64 connected to the manifold 52, a heater 66 for heating the manifold, and a control device 68 (i.e., CPU) for maintaining the manifold at a constant, desired temperature, similar to the temperature control system of each MFC 10. Specifically, the control device 68 is programmed to receive a desired vapor temperature from a user input device, and receive an indication of actual vapor temperature within the manifold 52 from the temperature measurement devices 64 (as indicated by control circuitry 70). The control device 68 then instructs the heater 66 (as indicated by control circuitry 72) to increase heat to the manifold 52 if the actual vapor temperature within the manifold is less than the desired vapor temperature, and instruct the heater to decrease heat to the manifold if the actual vapor temperature within the manifold is greater than the desired vapor temperature. Alternatively, a single temperature control system can be provided for the mass flow controller system 50 in place of the separate systems for each MFC 10 and the system for the manifold 52. Referring to FIG. 4, another mass flow controller system 80 according to the present disclosure is shown. The system 80 of FIG. 4 is similar to the system 50 of FIG. 3, and elements that are the same have the same reference numerals.
The system 80 includes a mass flow controller 110 for each of the plurality of vapor sources. The MFCs 110 of FIG. 4 are similar to the MFCs 10 of FIG. 3 except that the MFCs 110 are not provided with their own CPUs. Instead the system 80 is provided with a single control device (i.e., CPU) 82 connected to each of the MFCs 110 (as indicated by control circuitry 84) and connected to downstream pressure measurement device 54 (as indicated by control circuitry 86) of the manifold 52. The control device 82 controls the flow valves 22 of each MFC 110 based upon upstream and downstream pressure readings provided by the upstream pressure measurement devices 20 of the MFCs 110 and the downstream pressure measurement device 54 of the manifold 52. The control device 82 is also preferably connected to the temperature measurement devices 64 and the heater 66 (as indicated by confrol circuitry 88, 90) of the manifold 52, for maintaining the manifold at a constant, desired temperature.
By providing a single control device 82 for use by all of the MFCs 110, as opposed to providing each MFC with its own control device, among other benefits and advantages, a simpler and less expense mass flow control system 80 is provided.
Although a few exemplary embodiments of this disclosure have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this disclosure. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Claims

Claims:
1. A mass flow controller for controlling the flow rate of a fluid from a source, the mass flow controller comprising:
A) a flow path for connection to the source of fluid; B) a flow restrictor dividing the flow path into an upstream reservoir and a downstream reservoir;
C) an upstream pressure measurement device connected to the upsfream reservoir;
D) a flow valve connected to the flow path before the upstream reservoir;
E) a control device programmed to, i) receive and store a desired flow rate from a user input device, ii) receive an indication of upsfream pressure from the upstream pressure measurement device, iii) receive an indication of downstream pressure from a remote downstream pressure measurement device connected to the downstream reservoir, iv) determine an actual mass flow rate of fluid through the flow path in accordance with a linear function of the upstream pressure when the upsfream pressure is at least equal to about twice the downstream pressure, v) determine the actual mass flow rate of the fluid through the flow path in accordance with a nonlinear function of the upstream pressure and the downstream pressure when the upstream pressure is less than about twice the downstream pressure, vi) instruct the flow valve to increase flow if the actual flow rate is less than the desired flow rate, and vii) instruct the flow valve to decrease flow if the actual flow rate is greater than the desired flow rate.
2. A mass flow controller according to claim 1 , further comprising: A) at least one temperature measurement device connected to the flow path;
B) a heater for heating the fiowpath; and
C) the control device is also programmed to i) receive a desired fluid temperature from the user input device, ii) receive an indication of actual fluid temperature within the flow path from the temperature measurement device, iii) instruct the heater to increase heat to the flow path if the actual fluid temperature is less than the desired fluid temperature, and iv) instruct the heater to decrease heat to the flow path if the actual fluid temperature within the flow path is greater than the desired fluid temperature.
3. A mass flow controller according to claim 1, wherein the pressure measurement device comprises a pressure transducer.
.
4. A system for controlling the flow rates of fluids derived from a plurality of sources, the system including a mass flow controller according to claim 1 for each of the plurality of sources, and further comprising:
A) a manifold connecting the downstream reservoirs of the mass flow controllers; and
B) a downstream pressure measurement device connected to the manifold for providing an indication of the downstream pressure to the control devices of the flow controllers.
5. A system according to claim 4, further comprising valves connecting the downsfream reservoirs of the mass flow controllers to the manifold, whereby at least one of the mass flow controllers can be made to communicate with the manifold.
6. A system according to claim 4, further comprising:
A) a temperature measurement device connected to the manifold;
B) a heater for heating the manifold; and C) the control device is also programmed to i) receive a desired fluid temperature from the user input device, ii) receive an indication of actual fluid temperature within the manifold from the temperature measurement device, iii) instruct the heater to increase heat to the manifold if the actual fluid temperature within the manifold is less than the desired fluid temperature, and iv) instruct the heater to decrease heat to the manifold if the actual fluid temperature within the manifold is greater than the desired fluid temperature.
7.
A system according to claim 4, wherein the downstream pressure measurement device comprises a pressure transducer.
8. A system for controlling the flow rates of fluids derived from a plurality of sources, the system comprising:
A) a flow path for connection to each of the plurality of fluid sources;
B) flow restrictors dividing each of the flow paths into an upstream reservoir and a downstream reservoir; C) upsfream pressure measurement devices connected to each of the upstream reservoirs;
D) a manifold connecting the downsfream reservoirs of the mass flow controllers;
E) a downsfream pressure measurement device connected to the manifold;
F) a control device programmed to, for each flow path, i) receive an indication of upsfream pressure from the upsfream pressure measurement device of the flow path, ii) receive an indication of downstream pressure from the downsfream pressure measurement device, iii) determine an actual mass flow rate of fluid through the flow path in accordance with a linear function of the upstream pressure when the upstream pressure is at least equal to about twice the downstream pressure, and iv) determine the actual mass flow rate of the fluid through the flow path in accordance with a nonlinear function of the upsfream pressure and the downsfream pressure when the upstream pressure is less than about twice the downsfream pressure.
9. A system according to claim 8, wherein:
A) each flow path further includes a flow valve positioned before the upstream reservoir of the flow path; and
B) the controller is further programmed to, i) receive a desired flow rate from a user input device for each flow path, and ii) for each flow path, instruct the flow valve to increase flow if the actual flow rate is less than the desired flow rate, and instruct the flow valve to decrease flow if the actual flow rate is greater than the desired flow rate.
10. A system according to claim 8, further comprising valves connecting the downstream reservoirs of the flow paths to the manifold for selectively connecting the flow paths to the manifold.
11. A system according to claim 8, further comprising:
A) temperature measurement devices connected to the flow paths and the manifold;
B) heaters for heating the flow paths and the manifold; and C) the confrol device is also programmed to i) receive a desired fluid temperature from the user input device, ii) receive an indication of actual fluid temperature from the temperature measurement devices, iii) instruct the heaters to increase heat to the flow paths and the manifold if the actual fluid temperature is less than the desired fluid temperature, and iv) instruct the heaters to decrease heat to the flow paths and the manifold if the actual fluid temperature is greater than the desired fluid temperature.
12. A system according to claim 8, wherein the pressure measurement devices comprise pressure transducers.
13. A method for delivering fluids from a plurality of sources, comprising:
A) connecting a flow path to each source of fluid;
B) dividing each of the flow paths into an upstream reservoir and a downsfream reservoir; C) restricting fluid flow between the reservoirs of each of the flow paths;
D) determining a pressure in the manifold; and E) for each flow path, i) determining a pressure in the upstream reservoir of the flow path, ii) determine an actual mass flow rate of fluid through the flow path in accordance with a linear function of the upstream pressure when the upstream pressure is at least equal to about twice the downstream pressure, and iii) determine the actual mass flow rate of the fluid through the flow path in accordance with a nonlinear function of the upsfream pressure and the manifold pressure when the upstream pressure is less than about twice the downsfream pressure.
14. A method according to claim 13, further comprising:
A) receiving a desired flow rate from a user input device for each flow path; and
B) for each flow path, i) increasing fluid flow to the flow path if the actual flow rate is less than the desired flow rate, and ii) decreasing fluid flow to the flow path if the actual flow rate is greater than the desired flow rate.
15. A method according to claim 13, further comprising selectively connecting the flow paths to the manifold.
16. A method according to claim 13, further comprising:
A) measuring actual fluid temperature within the manifold; and
B) for each flow path, i) receiving a desired fluid temperature from the user input device, ii) measuring actual fluid temperature within the flow path, iii) increasing heat to the manifold if the actual fluid temperature in the manifold is less than the desired fluid temperature of the flow path, iv) decreasing heat to the manifold if the actual fluid temperature in the manifold is greater than the desired fluid temperature of the flow path, v) increasing heat to the flow path if the actual fluid temperature in the flow path is less than the desired fluid temperature of the flow path, and vi) decreasing heat to the flow path if the actual fluid temperature in the flow path is greater than the desired fluid temperature of the flow path.
PCT/US2001/024608 2000-12-26 2001-08-06 Pressure-based mass flow controller system WO2002052363A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019217078A1 (en) * 2018-05-07 2019-11-14 Mks Instruments, Inc. Methods and apparatus for multiple channel mass flow and ratio control systems

Families Citing this family (47)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002086632A2 (en) 2001-04-24 2002-10-31 Unit Instruments, Inc. System and method for configuring and asapting a mass flow controller
KR20040019293A (en) * 2001-05-24 2004-03-05 셀레리티 그룹 아이엔씨 Method and apparatus for providing a determined ratio of process fluids
US6962090B2 (en) * 2002-02-28 2005-11-08 Avl North America Inc. Heated stainless steel emissions canister
JP4528617B2 (en) * 2002-07-19 2010-08-18 セレリティ・インコーポレイテッド Method and apparatus for pressure compensation in a mass flow controller
GB2392506A (en) * 2002-07-23 2004-03-03 Alan Paul Troup A mass flow meter and controller therefor
US7063097B2 (en) 2003-03-28 2006-06-20 Advanced Technology Materials, Inc. In-situ gas blending and dilution system for delivery of dilute gas at a predetermined concentration
WO2004088415A2 (en) * 2003-03-28 2004-10-14 Advanced Technology Materials Inc. Photometrically modulated delivery of reagents
CN100454200C (en) * 2003-06-09 2009-01-21 喜开理株式会社 Relative pressure control system and relative flow control system
JP4454964B2 (en) * 2003-06-09 2010-04-21 東京エレクトロン株式会社 Partial pressure control system and flow rate control system
JP2005079141A (en) * 2003-08-28 2005-03-24 Asm Japan Kk Plasma cvd system
US7628861B2 (en) * 2004-12-17 2009-12-08 Mks Instruments, Inc. Pulsed mass flow delivery system and method
US7628860B2 (en) * 2004-04-12 2009-12-08 Mks Instruments, Inc. Pulsed mass flow delivery system and method
US20060060139A1 (en) * 2004-04-12 2006-03-23 Mks Instruments, Inc. Precursor gas delivery with carrier gas mixing
US7216019B2 (en) * 2004-07-08 2007-05-08 Celerity, Inc. Method and system for a mass flow controller with reduced pressure sensitivity
US20060130755A1 (en) * 2004-12-17 2006-06-22 Clark William R Pulsed mass flow measurement system and method
KR101241922B1 (en) 2005-06-22 2013-03-11 어드밴스드 테크놀러지 머티리얼즈, 인코포레이티드 Apparatus and process for integrated gas blending
US7680399B2 (en) * 2006-02-07 2010-03-16 Brooks Instrument, Llc System and method for producing and delivering vapor
US8448925B2 (en) 2006-10-17 2013-05-28 Mks Instruments, Inc. Devices, systems, and methods for carbonation of deionized water
US7706925B2 (en) * 2007-01-10 2010-04-27 Mks Instruments, Inc. Integrated pressure and flow ratio control system
US20080305014A1 (en) * 2007-06-07 2008-12-11 Hitachi Kokusai Electric Inc. Substrate processing apparatus
JP5001757B2 (en) * 2007-08-31 2012-08-15 シーケーディ株式会社 Fluid mixing system and fluid mixing apparatus
US20100229657A1 (en) * 2009-03-12 2010-09-16 Weinstein Jason P Sinter-bonded metal flow restrictor for regulating volumetric gas flow through an aerosol sampler inlet
US8712665B2 (en) * 2009-11-30 2014-04-29 General Electric Company Systems and methods for unchoked control of gas turbine fuel gas control valves
US9348339B2 (en) 2010-09-29 2016-05-24 Mks Instruments, Inc. Method and apparatus for multiple-channel pulse gas delivery system
US8997686B2 (en) * 2010-09-29 2015-04-07 Mks Instruments, Inc. System for and method of fast pulse gas delivery
US10031531B2 (en) 2011-02-25 2018-07-24 Mks Instruments, Inc. System for and method of multiple channel fast pulse gas delivery
US10353408B2 (en) 2011-02-25 2019-07-16 Mks Instruments, Inc. System for and method of fast pulse gas delivery
US10126760B2 (en) 2011-02-25 2018-11-13 Mks Instruments, Inc. System for and method of fast pulse gas delivery
US9188989B1 (en) 2011-08-20 2015-11-17 Daniel T. Mudd Flow node to deliver process gas using a remote pressure measurement device
US9958302B2 (en) 2011-08-20 2018-05-01 Reno Technologies, Inc. Flow control system, method, and apparatus
NL2009660C2 (en) * 2012-10-18 2014-04-22 Avantium Technologies B V Pressure controller.
WO2014152755A2 (en) 2013-03-14 2014-09-25 Christopher Max Horwitz Pressure-based gas flow controller with dynamic self-calibration
JP6107327B2 (en) * 2013-03-29 2017-04-05 東京エレクトロン株式会社 Film forming apparatus, gas supply apparatus, and film forming method
US20160160635A1 (en) * 2013-07-24 2016-06-09 Ikm Production Technology As Measurement device
EP3344953B1 (en) * 2015-08-31 2021-07-28 MKS Instruments, Inc. Method and apparatus for pressure-based flow measurement in non-critical flow conditions
US10684159B2 (en) * 2016-06-27 2020-06-16 Applied Materials, Inc. Methods, systems, and apparatus for mass flow verification based on choked flow
US10303189B2 (en) 2016-06-30 2019-05-28 Reno Technologies, Inc. Flow control system, method, and apparatus
US10838437B2 (en) 2018-02-22 2020-11-17 Ichor Systems, Inc. Apparatus for splitting flow of process gas and method of operating same
US11144075B2 (en) 2016-06-30 2021-10-12 Ichor Systems, Inc. Flow control system, method, and apparatus
US10679880B2 (en) 2016-09-27 2020-06-09 Ichor Systems, Inc. Method of achieving improved transient response in apparatus for controlling flow and system for accomplishing same
US10663337B2 (en) 2016-12-30 2020-05-26 Ichor Systems, Inc. Apparatus for controlling flow and method of calibrating same
JP6913498B2 (en) * 2017-04-18 2021-08-04 東京エレクトロン株式会社 Method of obtaining the output flow rate of the flow rate controller and method of processing the object to be processed
US9890908B1 (en) * 2017-04-18 2018-02-13 Air Products And Chemicals, Inc. Control system in a gas pipeline network to increase capacity factor
CN107894024B (en) * 2017-11-22 2023-08-18 新奥泛能网络科技股份有限公司 Control method and system of multi-source heating power pipe network
JP2021520544A (en) * 2018-04-03 2021-08-19 ラム リサーチ コーポレーションLam Research Corporation MEMS Coriolis gas flow controller
WO2022186971A1 (en) 2021-03-03 2022-09-09 Ichor Systems, Inc. Fluid flow control system comprising a manifold assembly
US20230369072A1 (en) * 2022-05-13 2023-11-16 Applied Materials, Inc. Systems and methods to reduce flow accuracy error for liquid & gas mass flow controller devices

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4951224A (en) * 1987-07-30 1990-08-21 Jiri Hokynar Control device for fluid flow
US5791369A (en) * 1995-06-12 1998-08-11 Fujikin Incorporated Pressure type flow rate control apparatus
US5868159A (en) * 1996-07-12 1999-02-09 Mks Instruments, Inc. Pressure-based mass flow controller
EP0969342A1 (en) * 1998-01-21 2000-01-05 Fujikin Inc. Fluid supply apparatus
US6074691A (en) * 1997-06-24 2000-06-13 Balzers Aktiengesellschaft Method for monitoring the flow of a gas into a vacuum reactor

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3851526A (en) 1973-04-09 1974-12-03 Tylan Corp Fluid flowmeter
US5282490A (en) * 1989-12-18 1994-02-01 Higgs Robert E Flow metering injection controller
DE69212129T2 (en) 1991-12-18 1997-01-23 Pierre Delajoud Mass flow meter with constricting element
US6296711B1 (en) * 1998-04-14 2001-10-02 Cvd Systems, Inc. Film processing system
US6454860B2 (en) * 1998-10-27 2002-09-24 Applied Materials, Inc. Deposition reactor having vaporizing, mixing and cleaning capabilities

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4951224A (en) * 1987-07-30 1990-08-21 Jiri Hokynar Control device for fluid flow
US5791369A (en) * 1995-06-12 1998-08-11 Fujikin Incorporated Pressure type flow rate control apparatus
US5868159A (en) * 1996-07-12 1999-02-09 Mks Instruments, Inc. Pressure-based mass flow controller
US6074691A (en) * 1997-06-24 2000-06-13 Balzers Aktiengesellschaft Method for monitoring the flow of a gas into a vacuum reactor
EP0969342A1 (en) * 1998-01-21 2000-01-05 Fujikin Inc. Fluid supply apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019217078A1 (en) * 2018-05-07 2019-11-14 Mks Instruments, Inc. Methods and apparatus for multiple channel mass flow and ratio control systems
US10698426B2 (en) 2018-05-07 2020-06-30 Mks Instruments, Inc. Methods and apparatus for multiple channel mass flow and ratio control systems
CN112204493A (en) * 2018-05-07 2021-01-08 万机仪器公司 Method and apparatus for a multi-channel mass flow and ratio control system
CN112204493B (en) * 2018-05-07 2024-01-09 万机仪器公司 Method and apparatus for a multi-channel mass flow and ratio control system

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