ToF-SIMS Analysis of Antimony Carboxylate EUV Photoresists

摘要

Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is used to evaluate the composition of nonvolatilephotoproducts created by EUV photolysis of antimony carboxylate photoresists [R_3Sb(O_2CR′)_2]. Dozens of potentialphotoproduct ions were identified using exact mass and ~(121)Sb/~(123)Sb isotopic ratios. Several oxygen-rich antimony ionswere found to increase in abundance with exposure. Two methods were employed to identify photoproducts whichcreate solubility contrast. First, samples were analyzed pre- and post-development to examine the effects of EUVexposure and developer solvent on secondary ion intensity. Secondly, changes in intensity of select ions were comparedto dissolution contrast over a range of doses. Through these studies, ion intensities were found to correlate withdissolution contrast for several fragments, indicating their active role in creating negative-tone response.