MKS Instruments, Inc.

Mass flow controllers that can provide for improved bleeding time and can be manufactured with less complexity and cost are provided. A mass flow controller includes a body having a valve outlet bore defining a flow path and an adjustable valve configured to control flow of a gas through the flow path. A valve element includes an outlet orifice of the adjustable valve and is disposed within the bore. The mass flow controller further includes a pressure drop element disposed coaxially with the valve element within the bore. An upstream pressure sensor is configured to detect a pressure at a location in the flow path between the adjustable valve and the pressure drop element, and a controller is configured to determine a flow rate through the flow path based on pressure as detected by the upstream pressure sensor.

A controller for a plasma generation system includes a model evaluation module receives a sensed value that varies in accordance with a state of a plasma controlled by a RF power generator. The model evaluation module generates a plasma parameter that varies in accordance with the sensed value. A model integration module receives the plasma parameter, integrates the plasma parameter, and outputs an integrated model parameter. An IEDF evaluation module receives the integrated model parameter and generates an ion energy distribution function (IEDF) in accordance with the integrated model parameter. An IEDF controller module receives the IEDF and generates a signal for controlling a RF generator. A RF generator control module receives the signal and generates an RF generator control signal to control at least one of power, frequency, or phase of the RF power generator.

A power supply system includes a RF power source configured to generate an output signal at an output frequency, a signal source configured to generate a perturbation signal, an extremum seeking frequency controller configured to generate a frequency control signal based on the perturbation signal, and a frequency selector configured to select a perturbation frequency of the perturbation signal that is isolated from at least one frequency tone associated with the power supply system. The frequency control signal varies the output frequency of the RF power source. Other example power supply system, methods for controlling a RF generator, and control systems for controlling a RF generator are also disclosed.

A monitoring system detects and measures a quantity of radical particles within a gas. A test chamber is coupled to a flow channel that transmits a gas. The test chamber defines an aperture connecting the test chamber and the flow channel, and the aperture permits a subset of the gas to enter the test chamber from the flow channel. An ionizer is positioned within the test chamber and generates radical ions from radical particles of the subset of the gas. A mass spectrometer measures a quantity of the radical ions, thereby providing a measurement of the radical particles in the gas.

A thermal conductivity gauge implements a model of power dissipation to accurately measure gas pressure. An envelope surrounds a gas volume, and a sensor wire is positioned within the gas volume. The controller provides a model of power dissipation from the thermal conductivity gauge, including power loss due to conductive heat loss from sensor wire end contacts, radiative loss from the sensor wire toward the gas envelope, and pressure dependent conductive heat loss from the sensor wire through surrounding gas. The controller then applies a power input to the sensor wire to heat the sensor wire, and measures total power dissipation W T , sensor wire temperature T s , and envelope temperature T e during the application of the power input. Gas pressure within the envelope is determined based on the measured W T , T s and T e and the model of power dissipation.

A plasma-generation system is provided that includes a variable-frequency microwave generator configured to generate microwave power and a plasma applicator configured to use the microwave power from the microwave generator to (i) ignite a process gas therein for initiating a plasma in a plasma ignition process and (ii) maintain the plasma in a steady state process. The system also includes a coarse tuner connected between the microwave generator and the plasma applicator. At least one physical parameter of the coarse tuner is adapted to be set to achieve coarse impedance matching between the microwave generator and the plasma generated during both the plasma ignition process and the steady state process. A load impedance of the plasma generated during the plasma ignition process and the steady state process is adapted to vary. The microwave generator is configured to tune an operating frequency at the set physical parameter of the coarse tuner.

A thermal conductivity gauge measures gas pressure within a chamber. A sensor wire and a resistor form a circuit coupled between a power input and ground, where the sensor wire extends into the chamber and connects to the resistor via a terminal. A controller adjusts the power input, as a function of a voltage at the terminal and a voltage at the power input, to bring the sensor wire to a target temperature. Based on the adjusted power input, the controller can determine a measure of the gas pressure within the chamber.

A system and method for dividing a single mass flow into secondary flows of desired ratios to total flow. Each secondary flow line includes a pressure drop element, an absolute pressure sensor and a differential pressure sensor. The nonlinear relationship between flow and pressures can be transformed into a function of the absolute and differential pressures that has a linear relationship with the flow.

A radio frequency (RF) generator system includes first and second RF power sources, each RF power source applying a respective RF signal and second RF signal to a load. The first RF signal is applied in accordance with the application of the second RF signal. The application of the first RF signal is synchronized to application of the second RF signal. The first RF signal may be amplitude modulated in synchronization with the second RF signal, and the amplitude modulation can include blanking of the first RF signal. A frequency offset may be applied to the first RF signal in synchronization with the second RF signal. A variable actuator associated with the first RF power source may be controlled in accordance with the second RF signal.

A power supply system includes a RF power source configured to generate an output signal at an output frequency, a signal source configured to generate a perturbation signal, an extremum seeking frequency controller configured to generate a frequency control signal based on the perturbation signal, and a frequency selector configured to select a perturbation frequency of the perturbation signal that is isolated from at least one frequency tone associated with the power supply system. The frequency control signal varies the output frequency of the RF power source. Other example power supply system, methods for controlling a RF generator, and control systems for controlling a RF generator are also disclosed.