Abstract: A method and apparatus for the controlled splitting of a fluid flow into multiple channels, where an input command specifies the flow in each channel as a percentage of the total flow. The flow in each channel is controlled by a valve capable of moving to a specified position, where the position is determined as a function of the specified percentage, the pressure upstream of the valve, and the pressure downstream of the valve.

Abstract: An apparatus for controlling the flow of a gas, containing a controllable valve, wherein the position of the valve and the gas pressure upstream of the valve are measured and used in conjunction with a first lookup table to determine the flow rate of the gas through the valve; and a flow restrictor upstream of the controllable valve, wherein the temperature of the flow restrictor and the gas pressure upstream and downstream of the flow restrictor are measured and used in conjunction with a second lookup table to determine the flow rate of the gas through the flow restrictor.

Abstract: A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Abstract: A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Abstract: A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Abstract: An apparatus for controlling the flow of a gas, containing a controllable valve, wherein the position of the valve and the gas pressure upstream of the valve are measured and used in conjunction with a first lookup table to determine the flow rate of the gas through the valve; and a flow restrictor upstream of the controllable valve, wherein the temperature of the flow restrictor and the gas pressure upstream and downstream of the flow restrictor are measured and used in conjunction with a second lookup table to determine the flow rate of the gas through the flow restrictor.

Abstract: A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Abstract: An apparatus to measure the transient response of a mass flow controller (MFC). The size of a variable orifice, upstream of the MFC, is controlled such that the pressure between the orifice and the MFC is held constant during the entire time that the MFC is going through its transient response. The known relationship between the size of the orifice and the flow through it allows a determination of the transient response of the MFC.

Abstract: A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Abstract: A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Abstract: Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. A pressure regulator is coupled to a gas source. The GFC is positioned downstream of the pressure regulator. A pressure transducer is measuring pressure in a volume between the pressure regulator and the GFC. Techniques are provided for increasing the pressure in the volume.

Abstract: Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test.

Abstract: Embodiments of the present invention employ measurement of argon as the means to detect the presence of an atmospheric leak in a processing chamber. Argon detected inside the process chamber is conclusive evidence of a leak. Furthermore, the amount of detected argon provides information on the rate of air entering through the leak. In one embodiment, leak detection takes place in the main plasma inside the processing chamber. In another embodiment, leak detection takes place in the self-contained plasma generated in a remote plasma sensor. Additional measurements can be performed, such as measuring the amount of oxygen, and/or the presence of moisture to help in detecting and quantifying outgassing from the processing chamber.

Abstract: Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. A pressure regulator is coupled to a gas source. The GFC is positioned downstream of the pressure regulator. A pressure transducer is measuring pressure in a volume between the pressure regulator and the GFC, wherein means are provided for increasing the pressure in the volume.

Abstract: An in-situ gas flow measurement controller measures the temperature and rate of pressure drop upstream from a flow control device (FCD). The controller samples the pressure and temperature data and applies the equivalent of a decimating filter to the data to produce filtered data at a slower sampling rate. The controller derives timestamps by counting ticks from the sampling clock of the A/D converter that is sampling the pressure at regular intervals to ensure the timestamps associated with the pressure samples are accurate and do not contain jitter that is associated with software clocks. The controller additionally normalizes the temperature reading to account for power supply fluctuations, filters out noise from the pressure and temperature readings, and excludes data during periods of instability. It calculates the gas flow rate accounting for possible non-linearities in the pressure measurements, and provides the computed gas flow measurement via one of many possible interfaces.

Abstract: An in-situ gas flow measurement controller measures the temperature and rate of pressure drop upstream from a flow control device (FCD). The controller samples the pressure and temperature data and applies the equivalent of a decimating filter to the data to produce filtered data at a slower sampling rate. The controller derives timestamps by counting ticks from the sampling clock of the A/D converter that is sampling the pressure at regular intervals to ensure the timestamps associated with the pressure samples are accurate and do not contain jitter that is associated with software clocks. The controller additionally normalizes the temperature reading to account for power supply fluctuations, filters out noise from the pressure and temperature readings, and excludes data during periods of instability. It calculates the gas flow rate accounting for possible non-linearities in the pressure measurements, and provides the computed gas flow measurement via one of many possible interfaces.

Abstract: An in-situ gas flow measurement controller measures the temperature and rate of pressure drop upstream from a flow control device (FCD). The controller samples the pressure and temperature data and applies the equivalent of a decimating filter to the data to produce filtered data at a slower sampling rate. The controller derives timestamps by counting ticks from the sampling clock of the A/D converter that is sampling the pressure at regular intervals to ensure the timestamps associated with the pressure samples are accurate and do not contain jitter that is associated with software clocks. The controller additionally normalizes the temperature reading to account for power supply fluctuations, filters out noise from the pressure and temperature readings, and excludes data during periods of instability. It calculates the gas flow rate accounting for possible non-linearities in the pressure measurements, and provides the computed gas flow measurement via one of many possible interfaces.

Abstract: Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. A pressure regulator is coupled to a gas source. The GFC is positioned downstream of the pressure regulator. A pressure transducer is measuring pressure in a volume between the pressure regulator and the GFC, wherein means are provided for increasing the pressure in the volume.

Abstract: Embodiments of the present invention relate to the analysis of the components of one or more gases, for example a gas mixture sampled from a semiconductor manufacturing process such as plasma etching or plasma enhanced chemical vapor deposition (PECVD). Particular embodiments provide sufficient power to a plasma of the sample, to dissociate a large number of the molecules and molecular fragments into individual atoms. With sufficient power (typically a power density of between 3-40 W/cm3) delivered into the plasma, most of the emission peaks result from emission of individual atoms, thereby creating spectra conducive to simplifying the identification of the chemical composition of the gases under investigation. Such accurate identification of components of the gas may allow for the precise determination of the stage of the process being performed, and in particular for detection of process endpoint.

Abstract: An apparatus to measure the transient response of a mass flow controller (MFC). The size of a variable orifice, upstream of the MFC, is controlled such that the pressure between the orifice and the MFC is held constant during the entire time that the MFC is going through its transient response. The known relationship between the size of the orifice and the flow through it allows a determination of the transient response of the MFC.