PRESSURE-BASED MASS FLOW CONTROLLER WITH REVERSE FLOW MODE FOR FAST BLEED DOWN
A gas delivery apparatus to overcome the shortcomings of the prior art by evacuating process gas upstream of a pressurized volume with a reverse flow mode.
1 . An electronic regulator to control delivery of a process gas to a semiconductor process at a specific mass flow rate, the electronic regulator using a reverse flow mode for fast bleed down of process gas responsive to a reduction to the specified mass flow rate, the electronic regulator comprising:
a processor; and
a memory, storing:
a controller to determine whether to operate in a forward mode in which process gas flows downstream to an accumulated volume or a reverse mode in which process gas flows upstream out of an accumulated volume,
a communication interface to receive external set points; and
a sensor interface to receive a current reading.