Recent progress on cutoff probe development for real time processing monitoring

The cut-off probe is the simplest of the plasma diagnostic tools made out of a simple intuition about the cut-off phenomenon of plasma waves, but it has had many problems to solve. Recently, the modeling development of the probe has revealed the physics behind the probe spectrum (S21), and the accuracy of probe measurements has been significantly improved. Now we believe it is time to move to semiconductor processing applications such as real-time processing monitoring for cut-off probes. In this talk, I would like to describe the recent progress in the development of cut-off probes for real-time plasma processing, such as planar cut-off probes, surface wave probes, including a brief historical review of cut-off probe research conducted over nearly two decades.