Optimization of Zr-Si compound films for attenuated PSM

This paper reports optimization of Zirconium-Silicon-Oxide (ZrSiO) films for attenuated phase shift mask (Att.PSM) concerning Zr/Si compound ratio. ZrSiO films were deposited by RF magnetron co-sputtering in Ar mixed with O2 gas using separated dual cathode of Zr and Si. Researched were the relationships between chemical durabilities, optical property, and Zr/Si compound ratio determined with XPS analysis. As a result, it was confirmed that controllability of optical property, chemical durabilities, and spectroscopic property would be improved by optimizing Zr/Si compound ratio. Consequently, by composing appropriate optical constants and thickness of bi-layer ZrSiO films, various transmitting Att.PSM can be obtained.