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.

Method and apparatus for gas flow control

An RF impedance matching network includes a transformation circuit configured to provide a transformed impedance; a first shunt circuit in parallel to the RF input, the first shunt circuit including a first shunt variable capacitance component comprising (a) a plurality of first shunt capacitors coupled in parallel, and (b) a plurality of first shunt switches coupled to the plurality of first shunt capacitors and configured to connect and disconnect each of the plurality of first shunt capacitors to a first virtual ground; and a second shunt variable capacitance component including (a) a plurality of second shunt capacitors coupled in parallel, and (b) a plurality of second shunt switches coupled to the plurality of second shunt capacitors and configured to connect and disconnect each of the plurality of second shunt capacitors to a second virtual ground.

RF impedance matching network

A mass flow controller and method for operating the same is disclosed. The mass flow controller includes a mass flow control system to control the mass flow rate of a fluid, and a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring condition types, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in a short term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type. A diagnostics component diagnoses failures using current functional parameter values and the statistical values stored in the short-term memory, and a prognostics component predicts failures based upon a collection of data sets that are stored in the long-term memory.

Mass flow controller with onboard diagnostics, prognostics, and data logging

A system for and method of delivering pulses of a desired mass of gas to a tool is described. A system for delivering pulses of a desired mass of gas to a process chamber or tool, comprising: a gas delivery chamber; a first valve arranged so as to control the flow of gas into the gas delivery chamber; a second valve arranged so as control the flow of gas leaving the gas delivery chamber so that the gas can leave the gas delivery chamber in pulses, each of a selected mass as a function of the initial pressure of the gas in the gas delivery chamber and the duration of the respective pulse; and a pressure control arrangement configured and arranged so as to control the flow of gas into the gas delivery chamber so as to precharge the gas in the gas delivery chamber to an initial pressure set point prior to delivering the pulses of gas such that the variance of the starting pressure of the gas in the gas delivery chamber is controlled prior to delivering the pulses of gas, and the repeatability of the mass delivery is improved as a function of the duration of each of the pulses.

System for and method of fast pulse gas delivery

A mass flow controller among other embodiments and method is described. The mass flow controller including a thermal mass flow sensor including at least two sensing elements coupled to a sensor tube of the mass flow controller, the thermal mass flow sensor being designed to provide a first signal indicative of flow of a gas within a first flow-rate-range and a second signal indicative of flow of the gas within a second flow-rate-range; and a control portion figured to control a valve position of the mass flow controller responsive to the first signal when the flow of the gas is within the first flow-rate-range and control the valve position of the mass flow controller responsive to the second signal when the flow of the gas is within a second flow-rate-range.

Mass flow controller with enhanced operating range

A system and method for controlling a flow of a fluid using a multi-mode control algorithm is described. One embodiment includes a method for changing the multi-mode control algorithm from a closed-loop mode to an open-loop mode. The method includes receiving at least one sensor indicator generated by a sensor. The multi-mode control algorithm is modified from the closed-loop mode to the open-loop mode when, based on the at least one sensor indicator, the threshold condition is satisfied. The multi-mode control algorithm is used by a flow controller to control a flow of a fluid according to a set point.

Multi-mode control algorithm

A mass flow controller (MFC), a method for calibrating an MFC, and a method for operating an MFC are disclosed. The method for calibrating the MFC includes obtaining data relative to two signals from a thermal mass flow sensor when operating the mass flow controller at different flow rates with a calibration gas, and storing the data relating to the two signals in connection with corresponding flow-rate values. The method for operating the MFC includes obtaining data relative to the two signals from the thermal mass flow controller and accessing the calibration data to determine an unknown flow rate for a process gas that may be the same gas as the calibration gas or may be another gas that is different from the calibration gas.

Method and mass flow controller for enhanced operating range

A system and method for delivering a specified-quantity of a fluid using a flow controller based on a fluid delivery profile is described. One embodiment includes a fluid delivery profile that includes a delivery time window with a plurality of set points that each correspond with a specified instant in time within the delivery time window. The method also includes delivering the fluid according to the fluid delivery profile through a variable valve using the flow controller and a feedback signal from a flow sensor.

Michael J. Zolock

Papers

Mass flow controller with onboard diagnostics, prognostics, and data logging

Mass flow controller with enhanced operating range

Multi-mode control algorithm

Method and mass flow controller for enhanced operating range

Flow controller delivery of a specified quantity of a fluid