Investigation of the angular dependences of the velocities of ion-beam sputtering of metals for the synthesis of mask blanks

An alternative material has been proposed as an absorber for a mask blank for lithography in the vicinity of a wavelength of 11.2 nm – Ni. It has been established in this work that the optimal angle for efficient sputtering of Ru, Be, and Ni targets by accelerated argon ion sources for fabrication of a Ru/Be multilayer structure with an upper Ni layer is an angle of 60$^\circ$ degrees. At this angle, the etching rate for all three materials is 35 $\pm$ 5 nm/min at an argon ion energy of 800 eV and an ion current density of 0.5 mA/cm$^2$.