Reducing capital and labor costs of 193nm lithography monitoring of airborne molecular contamination (AMC) through proactive assessment and implementation of AMC monitoring techniques and strategies

Abstract

Two methods for monitoring acid/base airborne molecular contamination (AMC) in 193nm lithography exposure tools, tracks, and process bays have historically been used for cleanroom and process contamination control. Ion Mobility Spectrometry (IMS) is a predominant technique used by semiconductor manufacturers for real-time AMC detection allowing for identification of subtle trends in AMC levels over time or alarming during high concentration events. Manual impinger sampling with ion chromatography (IC) analysis is a second technique used which pre-concentrates the air sample to allow for low detection limits and allows for some increased speciation of ions. The use of one or both of these techniques has a significant impact on the effectiveness of AMC detection and control, therefore, the equipment and strategy used within an AMC monitoring program can provide large competitive advantages that are not easily or quickly duplicated by other companies.