Evaluation of Inorganic-organic Hybrid Resist Materials with Ultrafast Coherent High Harmonic Generation (HHG) EUV System Developed in QST

In the realization of patterning feature sizes of sub-10 nm in semiconductor devices, it is essential to get new resist design strategies such as inorganic-organic hybrid resist materials for extreme ultraviolet (EUV) lithography. However, it is challenging for fundamental researchers to develop EUV resist materials due to the difficulty in obtaining experimental time for EUV exposure and limited EUV exposure tools, which are very expensive. Recently, we developed ultra-fast coherent EUV system based on high harmonics generation (HHG) and applied to EUV resist evaluation. In this study, the sensitivity of inorganic-organic hybrid resist materials known as metal-oxo clusters was evaluated by using this HHG EUV system. The obtained sensitivities were found to be comparable to the sensitivities obtained by conventional EUV flood exposure tool. It is concluded that the developed coherent HHG EUV system is very useful for sensitivity measurement of EUV resists and developing new EUV resists.