A Linear Single-Crystal Bragg-Fresnel Lens With SiO2 Surface Structure

Journal Article · Wed May 12 00:00:00 EDT 2004 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.1757903· OSTI ID:20653058

Kuznetsov, S; Yunkin, V ^[1]; Drakopoulos, M; Snigireva, I; Snigirev, A ^[2]

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1. Institute of Microelectronics Technology RAS, 142432 Chernogolovka Moscow distr. (Russian Federation)
2. ESRF, BP220, F-38043 Grenoble Cedex (France)

Bragg-Fresnel lens (BFL) as thin silicon dioxide strips grown on the surface of perfect silicon crystal was designed, manufactured and experimentally tested. In this case the BFL structure consists of a set of silicon dioxide rectangular shape etched zones arranged by the Fresnel zone law. The stress within coated and uncoated crystal regions is opposite in sign, whether tensile or compressive. The strain in the substrate crystal lattice directly underneath discontinuities in the deposited film give rise to phase difference between waves diffracted from coated and uncoated crystal regions. This phase difference is known to be dependent on the thickness and composition of film and substrate. The focusing properties of Si/SiO2 BFLs with 107 zones and 0.3 micrometer outermost zone width were experimentally studied as a function of the silicon oxide thickness in the range of 100 - 400 nanometers. It was shown that deformation Bragg-Fresnel lenses could effectively focus hard X-rays to a linear focal spot of about 2 microns. The efficiency of focusing was found to be about 16% at energy 10 keV. The developed lens design is a promising approach to extend the angular range of focusing by Bragg-Fresnel optical elements and to avoid some drawbacks of BFL properties related to aspect-ratio dependent etching.

• OSTI ID: 20653058
• Journal Information: AIP Conference Proceedings, Vol. 705, Issue 1; Conference: 8. international conference on synchrotron radiation instrumentation, San Francisco, CA (United States), 25-29 Aug 2003; Other Information: DOI: 10.1063/1.1757903; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ASPECT RATIO
BEAM OPTICS
BRAGG REFLECTION
CRYSTAL LATTICES
DIFFRACTION
ETCHING
FILMS
FOCUSING
FRESNEL LENS
HARD X RADIATION
KEV RANGE 10-100
MONOCRYSTALS
QUARTZ
SILICON
SILICON OXIDES
SUBSTRATES
SURFACES
SYNCHROTRON RADIATION
THICKNESS
ZONES