EUV Photochemistry of α-Substituted Antimony Carboxylate Complexes

We present a new class of EUV antimony carboxylate photoresists with enhanced reactivity and contrast, through the substitution of heteroatoms into the carboxylate. The lithographic performance of (C₆H₅)₃Sb(O₂CCH₂X)₂ photoresists in which X = methoxy, bromine or iodine is presented. The addition of iodine to the photoresist greatly improves dissolution contrast. Utilizing in-situ mass spectrometry, we show how the identity and degree of volatile photoproducts created during EUV exposure change with the composition of the heteroatom.