RF technology in semiconductor wafer processing

The radio frequency (RF) delivery system with its critical components including RF generators and matching networks for semiconductor wafer processing have been studied. In the design and implementation of RF generators, it is common practice to design PA modules for lower power levels and obtain higher power levels by paralleling them via combiner. RF generators have an internal directional coupler located right before an RF signal is sent to the matching network for sensing forward and reverse reflected powers and providing feedback signal to the system controller to maintain stability. Automated RF matching networks are critical components that provide the matched impedance interface to RF generator even when there is a change in the plasma impedance. One of the ways matching networks accomplish a tune point is to follow the changes in the impedance of the plasma using a device called Phase! Magnitude detector.