Real-time measurement of microwave resonators as plasma diagnostics for process monitoring

A method for monitoring a plasma property in real time, comprising:

• generating a chirped signal with a first frequency range;
• converting the first frequency range to a second frequency range that is higher than the first frequency range;
• providing the chirped signal to a resonator for interaction with a plasma, wherein a plasma modified resonant frequency of the resonator is measured by a reflected chirped carrier signal;
• converting the reflected signal to a third frequency range that is lower than the second frequency range;
• extracting a plasma property from the reflected signal.

A tool, comprising:

• a chamber suitable for generating a plasma;
• a pedestal within the chamber for supporting a substrate;
• and
• a sensor at least partially within the chamber for measuring plasma properties, wherein the sensor comprises:
• a resonator or transmission line;
• and
• RF circuitry coupled to the resonator, wherein the RF circuitry is configured to generate chirped pulses that are fed to the resonator.