CHROMATIC MONITORING FOR THE PROCESSING OF MATERIALS WITH PLASMAS

A non-invasive monitoring system for material-processing plasmas has b een developed based on chromatic modulation. The monitor consists of t wo parts, one for monitoring the emission spectra of plasmas and the s econd for monitoring the thickness of films on semiconductors during e tching or deposition. These chromatic systems offer significant speed advantages over equivalent spectroscopic techniques. Both systems have been tested on a variety of plasma chambers and typical results from both systems are presented. Chromatic monitoring provides rapid feedba ck on the state of a plasma and on film thickness, providing the possi bility for real-time monitoring and control of the plasma state. Furth er enhancement of the chromatic techique allows two-dimensional monito ring of the plasma, providing information on its uniformity.