Wi Seong Ju, Kim Won Jin, Kim Haneul, Jeong Dongmin, Lee Dong Gi, Choi Jaehyuck, Cho Sang Jin, Yu Lan, Ahn Jinho
Division of Materials Science and Engineering, Hanyang University, Seoul 04763, Republic of Korea.
EUV-IUCC (Industry University Cooperation Center), Hanyang University, Seoul 04763, Republic of Korea.
Membranes (Basel). 2023 Aug 14;13(8):731. doi: 10.3390/membranes13080731.
An extreme ultraviolet (EUV) pellicle is an ultrathin membrane at a stand-off distance from the reticle surface that protects the EUV mask from contamination during the exposure process. EUV pellicles must exhibit high EUV transmittance, low EUV reflectivity, and superior thermomechanical durability that can withstand the gradually increasing EUV source power. This study proposes an optimal range of optical constants to satisfy the EUV pellicle requirements based on the optical simulation results. Based on this, zirconium disilicide (ZrSi), which is expected to satisfy the optical and thermomechanical requirements, was selected as the EUV pellicle candidate material. An EUV pellicle composite comprising a ZrSi thin film deposited via co-sputtering was fabricated, and its thermal, optical, and mechanical properties were evaluated. The emissivity increased with an increase in the thickness of the ZrSi thin film. The measured EUV transmittance (92.7%) and reflectivity (0.033%) of the fabricated pellicle satisfied the EUV pellicle requirements. The ultimate tensile strength of the pellicle was 3.5 GPa. Thus, the applicability of the ZrSi thin film as an EUV pellicle material was verified.
极紫外（EUV）防护膜是一种与光刻掩膜表面保持一定距离的超薄膜，可在曝光过程中保护EUV掩膜免受污染。EUV防护膜必须具有高EUV透过率、低EUV反射率以及卓越的热机械耐久性，以承受逐渐增加的EUV光源功率。本研究基于光学模拟结果提出了满足EUV防护膜要求的光学常数最佳范围。在此基础上，选择有望满足光学和热机械要求的二硅化锆（ZrSi）作为EUV防护膜候选材料。制备了一种包含通过共溅射沉积的ZrSi薄膜的EUV防护膜复合材料，并对其热、光学和机械性能进行了评估。发射率随ZrSi薄膜厚度的增加而增加。所制备防护膜的实测EUV透过率（92.7%）和反射率（0.033%）满足EUV防护膜的要求。防护膜的极限抗拉强度为3.5 GPa。因此，验证了ZrSi薄膜作为EUV防护膜材料的适用性。
