- #1
Dever
- 10
- 0
Greetings,
I have shifted much of the focus of my research from thin film specifics to the plasma chamber we are using, as I was unfamiliar with the intricacies of plasma and found that a lot of the parameters we are counting on frankly could not be counted upon. I'm still green, but it's certainly restored my enthusiasm in research, as I find it fascinating! So my question:
I have a plasma generator used to power a 'semi-remote' radio-frequency (13.56 MHz) capacitive plasma in a custom-(poorly) built deposition system. I've attached a snapshot of a roughly-drawn schematic of the circuit for visualization of the problem. I'd like to determine the potential of the plasma electrode at a given output power and assuming match. The generator is supposed to see the standard 50 ohm impedance at the output, and it measures the reflected power, but doesn't give me any information about the expected potential past the matching network.
Won't I have to determine the impedance of the matching network in order to know the Vmax potential drop at the rf electrode? How can this be done at this frequency? I have an o-scope that measures the frequencies quite well, but it can't scale to the lowest output power of this generator (5 W). Even so, the models I'm seeing for the determination of impedance (applying a known resistor in series) [A] may fail at this frequency, and have only one source of impedance, not two matched sources.
The vast experience out there would be greatly appreciated.
I have shifted much of the focus of my research from thin film specifics to the plasma chamber we are using, as I was unfamiliar with the intricacies of plasma and found that a lot of the parameters we are counting on frankly could not be counted upon. I'm still green, but it's certainly restored my enthusiasm in research, as I find it fascinating! So my question:
I have a plasma generator used to power a 'semi-remote' radio-frequency (13.56 MHz) capacitive plasma in a custom-(poorly) built deposition system. I've attached a snapshot of a roughly-drawn schematic of the circuit for visualization of the problem. I'd like to determine the potential of the plasma electrode at a given output power and assuming match. The generator is supposed to see the standard 50 ohm impedance at the output, and it measures the reflected power, but doesn't give me any information about the expected potential past the matching network.
Won't I have to determine the impedance of the matching network in order to know the Vmax potential drop at the rf electrode? How can this be done at this frequency? I have an o-scope that measures the frequencies quite well, but it can't scale to the lowest output power of this generator (5 W). Even so, the models I'm seeing for the determination of impedance (applying a known resistor in series) [A] may fail at this frequency, and have only one source of impedance, not two matched sources.
The vast experience out there would be greatly appreciated.