Method of real time in-situ chamber condition monitoring using sensors and RF communication
Plural sensors on an interior surface of a reactor chamber are linked by respective RF communication channels to a hub inside the reactor chamber, which in turn is linked to a process controller outside of the chamber.
1. A reactor for processing a workpiece, the reactor comprising:
a chamber comprising:
a cylindrical sidewall;
a ceiling;
a floor; and
a pedestal for supporting a workpiece inside said chamber;
plural wireless sensors each having a wireless transceiver and secured to said chamber and fixed in locations inside said chamber;
a process controller outside of said chamber and connected to said chamber to govern process parameters in said chamber, wherein said cylindrical sidewall, said ceiling, and said floor are conductive such that said chamber blocks wireless communication channels between respective ones of said sensors and said process controller;
a wireless communication hub inside of said chamber and programmed to maintain respective independent wireless communication channels between the wireless transceiver of respective ones of said sensors and said wireless communication hub; and
a communication path between said wireless communication hub and said process controller.
2. The reactor of claim 1 wherein said process controller is programmed to repetitively sample all from a group of said sensors.
3. The reactor of claim 1 wherein said communication path between said wireless communication hub and said process controller comprises a wire conductor.
4. The reactor of claim 1 wherein said process controller is programmed to vary at least selected ones of said process parameters to conform outputs of selected ones of said sensors to desired values.
5. The reactor of claim 4 wherein said process parameters comprise one or more of: AC heater power, RF power supplied to an RF power applicator, coolant flow rate electrostatic chucking voltage and electrical power applied to a lift servo.
6. The reactor of claim 5 wherein said selected ones of said sensors comprise at least one of: a temperature sensor, a voltage sensor, a current sensor, a lift servo position sensor and an optical sensor.
7. The reactor of claim 1 wherein the locations comprise a workpiece support surface or an interior of the pedestal.
8. The reactor of claim 1 wherein the locations comprise the ceiling.
9. The reactor of claim 1 wherein said wireless communication hub is a first wireless communication hub, wherein said first wireless communication hub is inside said chamber and maintains respective independent RF communication channels between the wireless transceivers of a first group of individual ones of said sensors, respectively, and said first wireless communication hub, wherein said communication path is a first communication path, and the reactor further comprising:
a second wireless communication hub inside said chamber programmed to maintain respective independent RF communication channels between the wireless transceivers of a second group of individual ones of said sensors, respectively and said second wireless communication hub; and
a second communication path between said second wireless communication hub and said process controller.
10. The reactor of claim 9 wherein said first communication path between said first wireless communication hub and said process controller comprises a wire conductor, and wherein said second communication path between said second wireless communication hub and said process controller comprises a wire conductor.
11. The reactor of claim 9 further comprising an external wireless communication receiver outside of said chamber, wherein said first communication path between said first wireless communication hub and said process controller comprises a first wireless communication channel between said external wireless communication receiver and said first wireless communication hub, and wherein said second communication path between said second wireless communication hub and said process controller comprises a second wireless communication channel between said external wireless communication receiver and said second wireless communication hub.
12. The reactor of claim 1 wherein said communication path between said wireless communication hub and said process controller comprises:
an external wireless communication receiver outside of said chamber; and
a wireless communication channel between said external wireless communication receiver and said wireless communication hub.
13. The reactor of claim 12 further comprising an RF window in a wall of said chamber.