Multilayer X-ray mirrors based on La/B4C and La/B9C

The role of ultra-thin carbon barrier layers for fabrication of La/B4C interferential mirrors: Study by time-of-flight secondary ion mass spectrometry and high-resolution transmission electron microscopy

“…It decreases mirror reflectanceover a long period its maximal value has not exceeded 45-47%. An introduction of barrier layers of Cr, Mo and Sn exhibiting low chemical activities and adsorption of radiation near λ = 6.7 nm as well as using of B 9 C instead of B 4 C layers gave no significant effect [9]. Tsarfati et al [10,11] have concluded that deposition of barrier layers is an unpromising way for such pair of materials.…”

Manufacturing and Investigating Objective Lens for Ultrahigh Resolution Lithography Facilities

“…The spectral range around λ≈6.7 nm (area of boron anomalous dispersion) is of interest for projection x-ray lithography. However the reflectivity obtained here with La/B 4 C multilayer mirrors at a normal angle of incidence does not exceed 45-47 % (Andreev et al, 2009) that is not enough for lithographic applications. (Website ESRF, 2006;Andreev et al, 2003)) reflection coefficients of mostly attractive pairs of materials in X-ray and EUV ranges.…”

Next generation nanolithography based on Ru/Be and Rh/Sr multilayer optics

“…Systematic studies of La/B, La/B 4 C, La/B 9 C, and La 2 O 3 /B 4 C normalincidence multilayer mirrors showed that La/B 4 C multilayer structures (MLSs) had the best reflectivity. [12][13][14][15] To date, the maximum measured reflection coefficients were 44% at λ = 6.7 nm, 12 and 48.9% at λ = 6.68 nm. 15 We see strong discrepancy between the theoretical calculation, a value of more than 80%, and the experimental results.…”

“…The main reason for this discrepancy is the broadening of the transition boundaries in the multilayer structures, due to mixing of the materials. 13,14 In Refs. 13 and 16 it is shown also that in La/B 4 C multilayers, lanthanum forms compounds with boron and carbon (LaB 6 and LaC 2 ).…”