EUV resist outgassing quantification and application

The measurement 'lower limit' and repeatability of EUV resist outgassing analysis using the pressure rise and gas chromatography mass spectrometry (GC-MS) methods are investigated and discussed. Resist outgassing rate and amount measurement results showed a good repeatability with the application of the same method. As for measurement differences between dissimilar analysis methods (pressure rise and GC-MS), a relative difference of around 10 times was obtained. In addition, qualitative analysis performed using the GC-MS showed the need for clean measurement environment (significantly high vacuum conditions) to reduce the effect of background components affecting the measurement quality. Under such measurement conditions, an accurate analysis of the exact source of resist outgassing components was identified. As a result, it was confirmed that resist outgassing of the EUV resist is mostly composed of photo acid generator and protecting group byproducts.