Real Time AMC Monitoring with Novel Chemical Ionization Mass Spectrometry at Single-Digit pptv Concentrations

Abstract

In this study, emissions of photoresist resin deposited on wafters in a FOUP are compared using impinger/GCMS at-line measurements and on-line Vocus AMC measurements based on chemical ionization mass spectrometry. While GCMS measurements are routinely used for VOC measurements, the Vocus AMC monitor allows simultaneous, real-time detection of acids, bases, and condensable organics, providing unique insights into the cleanroom and FOUP microenvironment Photoresist resin outgassing measurements show comparable absolute concentrations between the two methods (GCMS and CI-TOF) for targeted compounds in real world sampling scenarios. The rate of outgassing was tracked in real time with the Vocus and also allowed identification of unknown compounds emitted from the resin. Continuous monitoring of the cleanroom air around the FOUP highlights the importance of the cleanroom environment which can directly affect the FOUP microenvironment, and additionally we show that Entegris Barrier Material EBM can guarantee a good wafer protection.