We are developing the EUV sensitizer for resists and Spin-on-Carbon materials. In previous report, we reported that we had developed the novel materials containing the iodine having high EUV absorption ability, and EUV absorption rate proved to be calculable from density and element composition. In this report, we calculated the improvement rate of the EUV absorption rate when materials with high EUV absorption were used for EUV sensitizers. As the result of this, we found that materials with high EUV absorption were useful for EUV sensitizers. Additionally, we will also report on new materials with a high EUV absorption ability.
In this paper, we designed the synthesis of negative-type molecular resist materials for EB and EUVL exposure tools, and their properties were examined. The resist materials for EUVL have been required showing higher sensitivity for high throughput in the lithographic process, and expecting lower shot noise to improve a roughness. In EUVL process, the resist materials must be ionized by absorbing EUV to emit more secondary electrons. The EUV absorption of the synthesized resist materials was measured using their thin films on the silicon wafer, and it was observed that the ratio of EUV absorption of the synthesized resist was higher than in the comparison of that of PHS as a reference., i.e., 2.4 times higher absorption was shown. Furthermore, we examined the relationship between the ratios of EUV absorptions and functional groups of the resist materials. As the result, the sensitivity of resist materials under EUV exposure tool was consistent with their structures.