%0 Journal Article
%A Parfeniukas, Karolis
%A Rahomäki, Jussi
%A Giakoumidis, Stylianos
%A Seiboth, Frank
%A Wittwer, Felix
%A Schroer, Christian
%A Vogt, Ulrich
%T Improved tungsten nanofabrication for hard X-ray zone plates
%J Microelectronic engineering
%V 152
%@ 0167-9317
%C [S.l.]
%I Elsevier
%M PUBDB-2016-05566
%P 6 - 9
%D 2016
%X We present an improved nanofabrication method of high aspect ratio tungsten structures for use in high efficiency nanofocusing hard X-ray zone plates. A ZEP 7000 electron beam resist layer used for patterning is cured by a second, much larger electron dose after development. The curing step improves pattern transfer fidelity into a chromium hard mask by reactive ion etching using Cl2/O2 chemistry. The pattern can then be transferred into an underlying tungsten layer by another reactive ion etching step using SF6/O2. A 630 nm-thick tungsten zone plate with smallest line width of 30 nm was fabricated using this method and characterized. At 8.2 keV photon energy the device showed an efficiency of 2.2
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000385991400002
%R 10.1016/j.mee.2015.12.015
%U https://bib-pubdb1.desy.de/record/315025