A method and apparatus for controlling the delivery of a gas from a reservoir to a semiconductor process chamber. In accordance with the present invention, a reservoir, having an inlet and outlet isolation valve and a known volume, is filled with a gas upon the initiation of process recipe step. The temperature and pressure of the gas in the reservoir are measured to determine an initial mass of the gas residing within the reservoir. The flow of gas from the reservoir to the process chamber is metered by a variable flow valve under the control of a self-calibrating, dynamic flow control circuit comprising a flow control servo loop (flow control circuit) and a calibration servo loop (calibration circuit). The variable flow valve is situated in a gas flow path between the reservoir and process chamber at a point upstream of a orifice. In operation, gas is delivered to the process chamber by releasing the gas from the reservoir and directing the gas through the variable flow valve and sonic orifice and into the process chamber. The flow control servo loop is used to dynamically control the variable flow valve in response to a measured gas flow rate. When the flow of gas to the process chamber is terminated, the temperature and pressure of the gas residing in the reservoir is again measured to determine the final mass of gas residing in the reservoir. The initial mass and final mass of gas values are compared to determine the actual mass of gas released from the reservoir during the recipe step. This value serves as an input to the calibration servo loop to update the system calibration constant. The execution of the calibration servo loop serves as a continuous self calibration of the dynamic servo loop.

Dynamic gas flow controller

Apparatus and a control system for monitoring (preferably digitally) and/or controlling pressure to a pneumatic load such as a proportional fluid control valve and using a measurement input from a fluid measurement device that responds to a flow rate, the liquid measurement input being used to control the pressure to the pneumatic load so that pneumatic load may be increased or decreased (to proportionally open or close the pneumatic valve) to change the flow rate of the fluid to a desired rate. The pneumatic load can also be adjusted (to proportionally open or close the pneumatic valve) to accommodate changes in temperature and viscosity of a fluid.

Liquid flow controller and precision dispense apparatus and system

A system and method for controlling a mass flow controller to have a constant control loop gain under a variety of different types of fluids and operating conditions, and for configuring the mass flow controller for operation with a fluid and/or operating conditions different from that used during a production of the mass flow controller. Further, the system and method includes providing control by reducing the effects of hysteresis in solenoid actuated devices by providing a non-operational signal to the solenoid actuated device.

System and method for a mass flow controller

A gas delivery system accurately measures and optionally regulates mass flow rate in real time. A fluid conduit connects an inlet valve, calibration volume, flow restrictor, and outlet valve in series. Pressure and temperature sensors are coupled to the calibration volume. One or more pressure sensors may be attached across the flow restrictor. Alternatively, an absolute pressure sensor may be attached upstream of the flow restrictor. One embodiment of differential pressure sensors comprises a floating reference differential pressure sensor, including a first transducer attached to the fluid conduit upstream of the flow restrictor and a second transducer attached to the conduit downstream of the flow restrictor. In this embodiment, each transducer receives a reference pressure from a reference source, and optionally, after the calibration volume is charged, the floating reference differential pressure transducers are calibrated. When gas flow is initiated, differential and/or absolute pressure measurements are repeatedly taken, and a measured mass flow rate calculated thereon. Gas flow is adjusted until the measured mass flow rate reaches a target mass flow. Using the temperature/pressure sensors at the calibration volume, repeated calculations of actual flow rate are made to uncover any discrepancy between actual and measured mass flow rates. Whenever a discrepancy is found, the manner of calculating measured mass flow is conditioned to account for the discrepancy; thus, the measured mass flow rate more accurately represents the actual mass flow rate thereby providing an actual mass flow rate more accurately achieving the target mass flow rate.

Method for wide range gas flow system with real time flow measurement and correction

An on-off device disposed at each of the inlet and the outlet of a fluid controller is one of five kinds of on-off devices, i.e., on-off device having a two-port valve, on-off device having a two-port valve and a three-port valve, on-off device having a two-port valve and two three-port valves, on-off device having two three-port valves, and on-off device having three three-port valves, The main bodies of two-port valves of all types of on-off devices are identical in configuration and each have an inlet and an outlet in a bottom face thereof. Main bodies of three-port valves of all types of on-off devices are identical in configuration and each formed in a bottom face thereof with an inlet, an outlet always in communication with the inlet, and an inlet-outlet subopening.

Fluid control apparatus

PROBLEM TO BE SOLVED: To provide a process gas supply unit which is compacted. SOLUTION: A process gas supply unit having an inlet opening and closing valve and an outletopening and closing vale which are an inlet solenoid valve and an outlet solenoid valve and a mass flow controller has a coil 32 coiled around an outer periphery of a hollow bobin 41, a fixed iron core 40 installed on a hollow part of the bobin 41 from the upper side and projected to the lower side, a movable iron core 33 to be attracted to the fixed iron core 40 at the time when the coil 32 is energized and a plate spring 34 whose inner periphery is fastened on the movable iron core and whose outer periphery is fastened on a solenoid valve main body and to energize the movable iron core in a direction where a valve seat 35 makes contact with a valve seat 39 at the time when the coil is not energized.

Process gas supply unit

In a flow quantity test system for a mass flow controller, a gas source for measurement is provided to supply gas for measurement. A cutoff valve for start of measurement is connected at its inlet port to the gas source for measurement and is connected at its outlet port to an inlet port of the mass flow controller. The cutoff valve for start of measurement is opened to flow the gas for measurement therethrough and closed to block the flow of the gas for measurement therethrough. A pressure gauge is provided to detect pressure of the gas for measurement appearing at the outlet port side of the cutoff valve for start of measurement. A microcomputer is provided to close the process gas cutoff valve and open the cutoff valve for start of measurement to change pressure detected by the pressure gauge. The microcomputer further closes the cutoff valve for start of measurement after pressure detected by the pressure gauge has reached predetermined pressure and measures lowering of pressure detected by the pressure gauge dependent on lapse of time after closing of the cutoff valve for start of measurement. Thereafter the microcomputer tests measuring precision of the mass flow controller in accordance with the measured lowering of the detected pressure.

Flow quantity test system for mass flow controller

PROBLEM TO BE SOLVED: To detect a failure of a diaphragm part even without removing the restriction part by providing a thermal type flow rate sensor that detects the flow rate of fluid passing through the restriction part and detects a fault of the restriction part. SOLUTION: Material gas is made to pass through an orifice 33 on sonic flow by maintaining the pressure ratio of an upstream of the orifice 33 to a downstream equally to or more than a fixed value. Then, the flow rate of the material gas can be controlled on the basis of upstream side pressure when the pressure ratio of the upstream of the orifice 33 to the downstream is maintained equally to or more than the fixed value. In the case corrosion gas is used for a gas supplying device for a long time, the orifice 33 corrodes away, a flow path is expanded in a diameter, and particles clog up in the flow path of the orifice 33 or the like so that an effective sectional area can sometimes be changed. A thermal type flow rate sensor 36 is provided on the upstream side of the orifice 33 to detect the change of this effective sectional area. That is, the sensor 36 detects the flow rate of the material gas passing through the orifice 33 in sonic flow and can detect the change of the effective sectional area from the flow rate change.

Gas supply controller

PROBLEM TO BE SOLVED: To stably gasify a liquid material, to easily produce gas and to enhance accuracy of control of the gasified gas. SOLUTION: A gasification device 3 heats the liquid material fed to a gasification chamber 25 of a housing 21 from a feed port 26 with a heater 12 to gasify, and discharges from a discharge port 27. A sintered body 28 is provided in the gasification chamber 25. The sintered body 28 is formed by compacting a powdery assembly having heat conductivity and anticorrosion property in a state having a specified porosity, and sintering. The gasification device 3 is provided with a control valve 11 for controlling a flow rate of the liquid material fed to the gasification chamber 25. The control valve 11 is provided with a valve body 44 and a seat 51, and the seat 51 has a feed port 26 in the center of it. One portion of the sintered body 28 is arranged in an adjacentnt relation to a feed port 26. A heater 12 provided on the outer periphery of the housing 21 works to heat the sintered body 28.

Gasification device of liquid material

PROBLEM TO BE SOLVED: To provide a remounting system of a process gas supply unit capable of remounting a module corresponding to each variation, in the process gas supply unit compact and in light weight. SOLUTION: In this process gas supply unit 1, mounting a check valve 11, a purge valve 12, a regulator 13 with interrupting function, a supply valve 15, and either one of a mass flow controller 14 or a sensor pack in a single base block 10 formed with flow paths 21 to 26, the mass flow controller 14 and the sensor pack can be remounted relating to the same base block 10.

Minoru Ito

Papers

Process gas supply unit

Flow quantity test system for mass flow controller

Gas supply controller

Gasification device of liquid material

Remounting system of process gas supply unit