Carbon K edge polarimetry with Cr Sc multilayers

We investigate the polarization changes simultaneously occurring with intensity changes due to carbon contamination of optical components at two plane grating beam lines PGM 1 and PGM 2 at BESSY II. The two beam lines are very similar to each other and connect to the same APPLE II type undulator UE56 2. The spectra measured with initial horizontal and vertical polarization differ for the two beam lines. For polarimetry measurements the BESSY 8 axis polarimeter is equipped with a Cr Sc multilayer in transmission as phase retarder and a Cr Sc reflecting multilayer operating near the Brewster angle as analyzer. The polarimetry results also differ for the two beam lines. Only at PGM 2 we observe no decline of the degree of polarization within experimental errors i.e. the degree of polarization at PGM 2 is always found P gt; 0.96. We find big changes of the polarization which rapidly vary across the carbon edge. A tentative interpretation predicts the orientation of the dipoles in the contaminating carbon layers. Circular polarization is largely recovered 80 and higher at PGM 2 thru out the carbon edge by setting the undulator shift to approximately compensate the polarizing properties of the beam lin

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

Ferromagnetic Co-C nanodot arrays produced by direct interferometric laser annealing

Magnetic properties of Co-C nanodot arrays produced by direct interferometric laser annealing are investigated by magnetic force microscopy (MFM) and magnetization measurements. The dots are formed by locally annealing sputtered amorphous Co-C films in regions where the laser intensity is highest. As-sputtered Co-C films do not exhibit ferromagnetic order at room temperature, but MFM shows that the dots become magnetic upon annealing, possibly due to the agglomeration or phase separation of Co-rich clusters. The dots are embedded in either a paramagnetic or weakly magnetic matrix. The magnetic properties of the generated pattern can be changed by varying the laser power. The present results show that direct interferometric lithography may become a useful tool for fabricating future patterned magnetic nanostructures