Impact of B4C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors

Ghafoor, Naureen; Eriksson, Fredrik; Aquila, Andrew; Gullikson, Eric; Schäfers, Franz; Greczynski, Grzegorz; Birch, Jens

doi:10.1364/OE.25.018274

Title: Impact of B₄C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors

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Abstract

We investigate the influence of B₄C incorporation during magnetron sputter deposition of Cr/Sc multilayers intended for soft X-ray reflective optics. Chemical analysis suggests formation of metal: boride and carbide bonds which stabilize an amorphous layer structure, resulting in smoother interfaces and an increased reflectivity. A near-normal incidence reflectivity of 11.7%, corresponding to a 67% increase, is achieved at λ = 3.11 nm upon adding 23 at.% (B + C). The advantage is significant for the multilayer periods larger than 1.8 nm, where amorphization results in smaller interface widths, for example, giving 36% reflectance and 99.89% degree of polarization near Brewster angle for a multilayer polarizer. The modulated ion-energy-assistance during the growth is considered vital to avoid intermixing during the interface formation even when B + C are added.

Authors:

Ghafoor, Naureen ^[1]; Eriksson, Fredrik ^[1]; Aquila, Andrew ^[2]; Gullikson, Eric ^[3]; Schäfers, Franz ^[4]; Greczynski, Grzegorz ^[1]; Birch, Jens ^[1]

Linkoping Univ. (Sweden). Dept. of Physics Chemistry and Biology
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Center for X-ray Optics
Inst. for Nanometer Optics and Helmholtz-Zentrum Berlin for Materials and Energy (Germany)

Publication Date:: Sun Jan 01 00:00:00 EST 2017

Research Org.:: SLAC National Accelerator Lab., Menlo Park, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1390702

Grant/Contract Number:: AC02-76SF00515

Resource Type:: Accepted Manuscript

Journal Name:: Optics Express

Additional Journal Information:: Journal Volume: 25; Journal Issue: 15; Journal ID: ISSN 1094-4087

Publisher:: Optical Society of America (OSA)

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE

Citation Formats


                    Ghafoor, Naureen, Eriksson, Fredrik, Aquila, Andrew, Gullikson, Eric, Schäfers, Franz, Greczynski, Grzegorz, and Birch, Jens. Impact of B4C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors.  United States: N. p., 2017. 
Web.  doi:10.1364/OE.25.018274.

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                    Ghafoor, Naureen, Eriksson, Fredrik, Aquila, Andrew, Gullikson, Eric, Schäfers, Franz, Greczynski, Grzegorz, & Birch, Jens. Impact of B4C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors.  United States.  https://doi.org/10.1364/OE.25.018274

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                    Ghafoor, Naureen, Eriksson, Fredrik, Aquila, Andrew, Gullikson, Eric, Schäfers, Franz, Greczynski, Grzegorz, and Birch, Jens. Sun .  
"Impact of B4C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors".  United States.  https://doi.org/10.1364/OE.25.018274.  https://www.osti.gov/servlets/purl/1390702.

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@article{osti_1390702,

  title        = {Impact of B4C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors},

  author       = {Ghafoor, Naureen and Eriksson, Fredrik and Aquila, Andrew and Gullikson, Eric and Schäfers, Franz and Greczynski, Grzegorz and Birch, Jens},

  abstractNote = {We investigate the influence of B4C incorporation during magnetron sputter deposition of Cr/Sc multilayers intended for soft X-ray reflective optics. Chemical analysis suggests formation of metal: boride and carbide bonds which stabilize an amorphous layer structure, resulting in smoother interfaces and an increased reflectivity. A near-normal incidence reflectivity of 11.7%, corresponding to a 67% increase, is achieved at λ = 3.11 nm upon adding 23 at.% (B + C). The advantage is significant for the multilayer periods larger than 1.8 nm, where amorphization results in smaller interface widths, for example, giving 36% reflectance and 99.89% degree of polarization near Brewster angle for a multilayer polarizer. The modulated ion-energy-assistance during the growth is considered vital to avoid intermixing during the interface formation even when B + C are added.},

  doi          = {10.1364/OE.25.018274},

  journal      = {Optics Express},

  number       = 15,

  volume       = 25,

  place        = {United States},

  year         = {Sun Jan 01 00:00:00 EST 2017},

  month        = {Sun Jan 01 00:00:00 EST 2017}

}

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Title: Impact of B4C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors

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Title: Impact of B₄C co-sputtering on structure and optical performance of Cr/Sc multilayer X-ray mirrors