Pulse radiolysis of methacrylic acid ligand for zirconia nanoparticle resist

The trade-off relationships between resolution, line width roughness (LWR) and sensitivity is the most serious problem in the development of resist materials. Metal oxide nanoparticle resists are expected to overcome such a trade-off problem. Understanding the sensitization mechanism is important for the efficient development of metal oxide nanoparticle resists. However, the sensitization mechanism of the metal oxide nanoparticle resists is still unknown. In this study, the radiation-induced reactions of methacrylic acid (MAA) ligands for zirconia (ZrO2) nanoparticle resists were investigated using a pulse radiolysis method. Both the reaction paths through MAA radical cation and MAA radical anion are considered to lead to the insolubilization of the zirconia nanoparticle resists. The acid generators suppressed LWR, probably through capturing the thermalized electrons.