Method and apparatus for gas flow measurement
AssigneeApplied Materials, Inc.
InventorsJared Ahmed Lee, Ezra Robert Gold, Chunlei Zhang, James Patrick Cruse, Richard Charles Fovell
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Abstract
A method and apparatus for measuring gas flow are provided. In one embodiment, a calibration circuit for gas control may be utilized to verify and/or calibrate gas flows utilized for backside cooling, process gas delivery, purge gas delivery, cleaning agent delivery, carrier gases delivery and remediation gas delivery, among others.
Claims20
Apparatus for delivering gas in a processing system having a processing chamber, comprising:
- a gas source;
- a diverter valve having an inlet, a first outlet and a second outlet, the second outlet coupled to the processing chamber;
- a regulating device fluidly coupled between the gas source and the inlet of the diverter valve;
- an orifice fluidly coupled to the first outlet of the diverter valve, the orifice having substantially the same flow resistance as the processing chamber;
- and
- a sensing circuit configured to receive flow passing through the orifice, wherein the sensing circuit comprises:
- a sensor;
- a by-pass loop around the sensor;
- a tank;
- and
- a valve diverting the flow from the orifice between the tank and the by-pass loop.
A method for calibrating a flow control device in a semiconductor processing system, comprising:
- setting a gas flow with the flow control device;
- flowing the gas from the flow control device through an orifice having substantially the same flow resistance as a processing chamber into a sensing circuit;
- flowing the gas into a volume of the sensing circuit;
- sensing at least one property and/or attribute of the gas in the volume;
- resolving a flow rate and/or pressure of the gas entering the sensing circuit from the sensed property and/or attribute;
- and
- comparing a flow determined using the sensing circuit with the setting of the flow control device.
A method for calibrating a flow control device, comprising:
- setting a gas flow with the flow control device;
- flowing the gas from the flow control device through an orifice having substantially the same flow resistance as a processing chamber into a sensing circuit;
- comparing a flow determined using the sensing circuit with the setting of the flow control device;
- and
- sampling a characteristic of a gas present in the sensing circuit until an endpoint is reached.
A method for providing a process gas in a semiconductor processing system, comprising:
- providing a processing system having a gas source coupled to a processing chamber and sensing circuit, the sensing circuit having substantially the same flow resistance as the processing chamber;
- setting a flow control device to provide a flow of process gas from the gas source at target rate, the target rate being a predefined rate selected for substrate processing in the processing chamber, the flow exiting the flow control device being at an actual rate;
- flowing the process gas at the actual rate into the sensing circuit while bypassing the processing chamber;
- sensing a metric indicative of the actual flow rate;
- adjusting the setting of the flow control device to correct differences between the actual rate and the target rate;
- and
- flowing the process gas from the flow control device into the processing chamber and processing a substrate therein.
Dependencies are inferred from the claim text.