Highly reflective Ru Y multilayer mirrors for the spectral range of 9 11 nm

The results of the investigation of the reflective characteristics of multilayer mirrors based on Ru Y are presented. Reflection coefficients at the level of 38.5 at an operating wavelength of 9.4 nm. It is shown that the deposition of B4C barrier layers onto Y layers makes it possible to significantly increase the reflection coefficient compared to structures without barrier layers. A reflectance of 54 was obtained for mirrors optimized for 11.4 nm, which is close to the theoretical limit for these material

Evolution of Interface Structure in Ni-C Multilayers Depending on Annealing Temperature : Use of Embedded Co Sublayers-Markers

To verify the mechanism of epitaxial self-smoothing of interfaces in Ni(Co)/C multilayers annealed at optimum temperature, Ni/C multilayers with embedded Co atoms-markers at a desired depth were studied. This depth-resolving EXAFS technique shows that mixed interfaces are separated at first stages of annealing followed by the crystallization of metal layers at the higher temperatures. The temperature of the interface separation coincides very closely with the temperature observed for a maximum multilayer reflectivity. These results are well explained by the decomposition of the metal glass-like region with carbon excess at the interface, simultaneously with coherent growth of metal (111) and graphite layers. Further bulk crystallization of the metal layers leads to the enhancement of interface roughness, and hence to a drastic decrease in reflectivity

High performance La B4C multilayer mirrors with C barrier layers for the next generation lithography

Results on optimization and manufacturing of La B4C multilayers are reported. Such mirrors are promising optical elements for the development of the next generation of nano lithography at an operation wavelength of 6.7 nm. A near normal incidence reflectivity of up to 58.6 has been measured at the BESSY II soft x ray reflectometer beamline. This is the highest reflectivity measured so far at this wavelength. The potential to further increase the reflectivity of the multilayers is discusse

Effect of roughness, deterministic and random errors in film thickness on the reflecting properties of aperiodic mirrors for the EUV range

By the example of three aperiodic multilayer Mo sI MIRRORS AMM for the wavelength ranges 17 21 nm, 24 29 nm, and 28 33 nm we have studied numerically the effect of the linearly deterministics and random fluctuations of the film thickness and the interlayer roughness on the spectral dependencies of the reflection coefficient. The simulation results are used to solve the inverse problem of reconstructing the interlayer roughness and the thickness of individual films from the measured dependencies of the extreme UV radiation reflection coefficients. It is shown that the asymmetry of the boundaries affects the magnitude and slope of the reflection coefficient plateau. Random fluctuations of the film thickness with the variance of 1 2 weakly influence the reflection characteristics of AMMs and allow reliable reconstruction of the thickness of individual films. The fluctuations with the variance 8 10 allow the estimation of individual thicknesses, but the reflection curve in this case strongly differs from the desirable one. Larger fluctuations do not allow the reconstruction of the AMM structure. The basic criteria for high quality AMM synthesis are formulate