Model reactivity of inorganic and organometallic materials in EUV (Conference Presentation)

The looming industry transition towards EUV for high-volume manufacture of semiconductors has demonstrated the need for high sensitivity resists capable of delivering the resolution enhancements offered by the 13.5 nm platform. Inorganic and organometallic based resists have demonstrated themselves viable alternatives to traditional chemically amplified (CA) photoresists, as the EUV absorptivity enhancement of metal nuclei can enable efficient reactivity at minimal photon doses. Despite the demand for EUV photoreactive materials, relatively little has been reported on the fundamental reactivity of inorganic and organometallic compounds towards EUV that may enable the rational design of metal-based resists. To facilitate the design of next-generation metal-based resists, we have evaluated the reactivity of well-known metal-based model photosystems that undergo ligand-to-metal charge-transfer (LMCT), metal-to-ligand charge-transfer (MLCT), outer-sphere charge-transfer (OSCT), and ligand field (LF) based photochemistry in the UV and visible towards EUV and 100 KeV e-beam, with product characterization carried out by infrared, Raman, and UV-Vis spectroscopies. We will report the findings of these studies, emphasizing the relationships between quantum yields in the UV-Vis and EUV, role of the EUV absorption cross-section of the central metal, and trends in reaction classes and their relative sensitivity towards EUV.