Isotopic Labeling Studies of EUV Photoresists Containing Antimony

Michael Murphy, Jacob Sitterly, Steven Grzeskowiak, Greg Denbeaux, Robert L. Brainard
2018 Journal of Photopolymer Science and Technology (Fotoporima Konwakai shi)  
We have investigated the mechanism of photodecomposition of antimony carboxylate complexes of the type Ph 3 Sb(O 2 CR′) 2 by means of EUV outgassing in combination with isotopic labeling. When exposed to EUV light, these compounds decompose to form CO 2 , benzene and phenol. The source of hydrogen needed to create phenol can be traced to hydrogens originating in the original organometallic complex. However, it is much more difficult to trace the origin of the hydrogen needed to convert the
more » ... l groups to benzene (Ph-H). We propose that the primary source of hydrogen to create benzene is external to the film. Additionally, we have prepared isotopically-labeled versions of Ph3Sb(O2CCH(CH3)2)2 in which the hydrogens in the isobutyrate ligand were replaced with 0, 1, 6 and 7 deuteriums, to provide information about the relative reactivity of these protons during EUV exposure as analyzed by mass spectrometry. High reaction selectivity was identified within the carboxylate dictated by hydrogen location relative to the carbonyl for both benzene and phenol generation. Lastly, the results of these studies were used to propose a series of reaction pathways to generate the aforementioned reaction byproducts.
doi:10.2494/photopolymer.31.233 fatcat:q62vatmlaffpvm7dzca2khgm2e