抄録
Investigations on the resist film depth-profile of a Zr-based EUV metal resist (which contains methacrylic acid or MAA as shell) reveal that the metal cores (Zr) are homogeneously distributed across the film-depth. However, the shell molecules (MAA) in the same resist film have an inhomogeneous distribution (relatively high concentration at the film surface compared to the film bottom). In addition, the total concentration of shell molecules across the film depth is significantly affected (decreases) due to post coating delay and increased exposure dose. Moreover, it is confirmed that the existence of such metal resist film depth inhomogeneities affects the resist’s dissolution properties in the developer solution. Specifically, variations in metal resist dissolution characteristics between the film surface, mid-film, and the film bottom are observed. These results confirm the impact of metal resist film properties on its solubility in the developer solution, which can directly affect patterning performance (resolution, line edge/width roughness (LER/LWR), and sensitivity), especially LER/LWR.
