Synthesis and structural analysis of Mo/B periodical multilayer X-ray mirrors for beyond extreme ultraviolet optics

• DOI: 10.1016/j.matdes.2020.109318
• Publication Date: 2020-11-11T20:40:57Z
• Authors: Oleksiy V. Penkov; Igor A. Kopylets; Valeriy V. Kondra...; Mahdi Khadem
• Keywords: Reflectometry; Extreme ultraviolet; Extreme Ultraviolet Lithography; X-ray optics

The synthesis and structural analysis of Mo/B periodical multilayer X-ray mirrors (PMMs) for beyond extreme ultraviolet (BEUV) optics was performed. PMMs were deposited by a combination pulsed DC radio frequency (RF) magnetron sputtering. structure analyzed high-resolution transmission electron microscopy, photoelectron spectroscopy, grazing incidence reflectometry. formation 0.35 nm-thick interlayers comprised mixture molybdenum borides observed at the interfaces. Furthermore, low interface roughness 0.3–0.4 nm reported. temperature substrate increased due to increase in sputtering power. This resulted an thickness roughness; subsequently, optical properties PMM deteriorated. Theoretical calculations performed based on real predict reflectivity working wavelength 6.7 nm. approximately 53% two times higher than that conventional B4C-based BEUV mirrors. Based our study results, it can be concluded as-synthesized will perform better traditional effectively used development next generation lithography.