title: A unique approach to accurately measure thickness in thick multilayers.
abstract: X-ray optics called multilayer Laue lenses (MLLs) provide a promising path to focusing hard X-rays with high focusing efficiency at a resolution between 5 nm and 20 nm. MLLs consist of thousands of depth-graded thin layers. The thickness of each layer obeys the linear zone plate law. X-ray beamline tests have been performed on magnetron sputter-deposited WSi(2)/Si MLLs at the Advanced Photon Source/Center for Nanoscale Materials 26-ID nanoprobe beamline. However, it is still very challenging to accurately grow each layer at the designed thickness during deposition; errors introduced during thickness measurements of thousands of layers lead to inaccurate MLL structures. Here, a new metrology approach that can accurately measure thickness by introducing regular marks on the cross section of thousands of layers using a focused ion beam is reported. This new measurement method is compared with a previous method. More accurate results are obtained using the new measurement approach.
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA. shi@anl.gov
authors.forename: Bing
authors.initials: B
authors.lastname: Shi
authors.forename: Jon M
authors.initials: JM
authors.lastname: Hiller
authors.forename: Yuzi
authors.initials: Y
authors.lastname: Liu
authors.forename: Chian
authors.initials: C
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Qian
authors.forename: Lisa
authors.initials: L
authors.lastname: Gades
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wieczorek
authors.forename: Albert T
authors.initials: AT
authors.lastname: Marander
authors.forename: Jorg
authors.initials: J
authors.lastname: Maser
authors.forename: Lahsen
authors.initials: L
authors.lastname: Assoufid