A study of the interactions between surfaces, neutral gas and the plasma in low-temperature discharges.

University Of Texas At Dallas, Richardson TX

Investigators

Abstract

The goals of this study are to improve fundamental understanding of the physical and chemical processes that occur on the walls of low-temperature plasma systems and to develop an understanding of how these wall processes feed back to the plasma chemistry and influence the basic properties of the glow. Experimental and computational investigations are combined to address these issues. Measurements of fundamental parameters of plasmas are made in a modified Gaseous Electronics Conference (GEC) reference cell and compared with results from a comprehensive plasma equipment simulator, the Hybrid Plasma Equipment Model (HPEM). The emphasis is on processes occurring on chamber walls and their influence on the overall discharge. Diagnostics used include Langmuir probe measurements, microwave interferometry, Fourier-transform infrared (FTIR) spectrometry, mass and energy analysis, optical emission spectrometry (OES), and surface reflection techniques. Interactions between working gases and the walls that contain them occur in all terrestrial low-pressure plasmas such as those used for semiconductor processing, lighting, and lasers. These interactions can determine the basic parameters of the glow, but have received little direct study. This work will provide a basis for a rational approach to the design, cleaning, or "seasoning" of plasma chambers.