A conceptual design of a Reactive Ion Etch back end system for the direct reuse of process gases

Abstract

The use of Plasma Etching, specifically Reactive Ion Etching (RIE), is a vital tool in manufacturing semiconductor devices. Most gases used in RIE processes were initially chosen because of their relatively low toxicity and reactivity. However, many of these gases have proven to be detrimental to the environment. Because of the low percentage of utilization of the gas in a plasma process, these effects are a major concern. Few methods exist in industry today to dispose of unused gases, and all of the known abatement processes produce some byproduct that must also be disposed. This work proposes a system to be attached to the exhaust of a RIE etch system that will reprocess etch gases for immediate use. This work win show that such a system is feasible at a relatively low cost. Reclaiming and reprocessing the etch gas will take several distinct steps. The different technologies that accomplish each step will be explained as well as why these technologies were chosen. An explanation of why such a process is advantageous from a non-environmental standpoint will also be given. Suggestions on how an actual system should be built will be given. A synopsis on the future plans of this program will also be presented.