Abstract: A mole delivery system and method provide pulses of known molar quantities as a function of the time duration of each pulse, which in turn is derived as a function of the ideal gas law. In one embodiment of the system, the system comprises: a chamber of known volume and controlled and known temperature; a pressure sensor to measure the pressure in the chamber; an outlet valve to a process tool; an inlet valve to charge the chamber with the delivery gas; and a control system configured and arranged so as to control the operation of the outlet valve, control the amount of each gas pulse by controlling the timing of the valve to the process tool.

Abstract: A mole delivery system and method provide pulses of known molar quantities as a function of the time duration of each pulse, which in turn is derived as a function of the ideal gas law. In one embodiment of the system, the system comprises: a chamber of known volume and controlled and known temperature; a pressure sensor to measure the pressure in the chamber; an outlet valve to a process tool; an inlet valve to charge the chamber with the delivery gas; and a control system configured and arranged so as to control the operation of the outlet valve, control the amount of each gas pulse by controlling the timing of the valve to the process tool.

Abstract: A flow rate sensor includes a main conduit, a sensor tube and a bypass tube connecting an upstream portion of the main conduit to a downstream portion of the main conduit such that flow through the main conduit is divided through the sensor tube and the bypass tube, and at least one heater element for heating the sensor tube. A first flow restrictor of porous media is positioned between the upstream portion of the main conduit and the sensor tube, and a second flow restrictor of porous media is positioned between the upstream portion of the main conduit and the bypass tube. The flow restrictors provide the flow rate sensor with a fixed bypass ratio so that the sensor can operate independently of the type of gas being measured.

Abstract: A vaporizer including an inlet for liquid and an outlet for gas, a gas valve controlling gas flow to the outlet of the vaporizer, and means for heating liquid flowing between the liquid inlet and the gas valve. The vaporizer also includes means for increasing a heat transfer rate of the liquid flowing between the liquid inlet and the gas valve, and for causing a pressure drop in the liquid so that a pressure of the liquid drops below a vapor transition pressure of the liquid upon reaching the gas valve. The pressure drop occurs under isothermal conditions, and the liquid is vaporized on demand only when the valve is opened. The means for increasing a heat transfer rate and for causing a pressure drop can be a plug of porous media.

Abstract: A sensing apparatus for use in a mass flow rate sensor for measuring a fluid flow rate includes a main conduit for containing a fluid flow, and a sensor passageway for tapping a portion of the fluid flow from the main conduit at a first location, and returning the portion of the fluid flow to the conduit at a second location. At least one bypass passageway, which may be provided in the form of a tube, is positioned in the main conduit between the first and second locations, and the bypass passageway is provided with non-negligible entrance effects that are substantially equal to entrance effects of the sensor passageway, so that a bypass ratio of the apparatus remains constant. A mass flow rate sensor of the present disclosure accurately measures any type of gas but only requires calibration in only one reference gas.

Abstract: A flow rate sensor includes a main conduit, a sensor tube and a bypass tube connecting an upstream portion of the main conduit to a downstream portion of the main conduit such that flow through the main conduit is divided through the sensor tube and the bypass tube, and at least one heater element for heating the sensor tube. A first flow restrictor of porous media is positioned between the upstream portion of the main conduit and the sensor tube, and a second flow restrictor of porous media is positioned between the upstream portion of the main conduit and the bypass tube. The flow restrictors provide the flow rate sensor with a fixed bypass ratio so that the sensor can operate independently of the type of gas being measured.

Abstract: A sensing apparatus for use in a mass flow rate sensor for measuring a fluid flow rate includes a main conduit for containing a fluid flow, and a sensor passageway for tapping a portion of the fluid flow from the main conduit at a first location, and returning the portion of the fluid flow to the conduit at a second location. At least one bypass passageway, which may be provided in the form of a tube, is positioned in the main conduit between the first and second locations, and the bypass passageway is provided with non-negligible entrance effects that are substantially equal to entrance effects of the sensor passageway, so that a bypass ratio of the apparatus remains constant. A mass flow rate sensor of the present disclosure accurately measures any type of gas but only requires calibration in only one reference gas.

Abstract: A system and method are described that control the amount of precursor that is delivered to a process chamber by precisely measuring the mole fraction of the gas mixture being delivered. A gas delivery system includes a delivery chamber, a precursor inlet valve, a carrier inlet valve, an outlet valve, and a controller. The controller controls the opening and closing of the precursor inlet valve, the carrier inlet valve, and the outlet valve, so as to introduce a desired amount of a precursor gas and a carrier gas into the delivery chamber, to generate a gas mixture having a desired mole fraction of the precursor gas, and to deliver to the process chamber the gas mixture having the desired mole fraction of the precursor gas.

Abstract: A mass flow rate sensor uses a Reynolds number correction function to compensate for errors in a bypass ratio of the sensor for all gases, based on the fact that all bypass errors are functions of Reynolds number. The sensor includes a sensor tube and a bypass tube dividing flow, wherein a bypass ratio of the sensor equals a total flow rate through the sensor divided by a flow rate through just the sensor tube. Heater elements heat an upstream portion and a downstream portion of the sensor tube, and a circuit is connected to the heater elements for producing a voltage based upon a difference in resistance between the heater elements. The voltage is calibrated based on known flow rates of a reference gas, and the flow rate through the sensor is based upon the calibrated voltage multiplied by a multi-gas correction function and a Reynolds number correction function.

Abstract: A sensing apparatus for use in a mass flow rate sensor for measuring a fluid flow rate includes a main conduit for containing a fluid flow, and a capillary tube for tapping a portion of the fluid flow from the main conduit at a first location, and returning the portion of the fluid flow to the conduit at a second location. The capillary tube is disposed about a centerline, and includes an inner wall defined by an inside radius measured from the centerline. The inside radius varies periodically, preferably sinusoidally, along the centerline for at least a portion of the capillary tube, thereby forming a turbulated surface on the inner wall. The turbulated inner wall increases wall surface area, and fluid mixing. The resulting increased heat transfer rate decreases the error in sensor output from nonlinear behavior.