Blazed, grazing incidence x-ray reflection gratings are an important component of modern high resolution spectrometers and related x-ray optics. These have traditionally been fabricated by diamond scribing in a ruling engine, or more recently by interferometric lithography followed by ion etching. These traditional methods result in gratings which suffer from a number of deficiencies, including high surface roughness and poor control of the groove profile. These deficiencies lead to poor diffraction efficiency and high levels of scattered light. We have developed a novel fabrication method for fabricating blazed x-ray reflection gratings which utilizes silicon wafers that are cut 0.7° off of the (111) plane. In solutions such as potassium hydroxide (KOH), silicon is etched in 〈111〉 directions orders of magnitude slower than in other directions, resulting in extremely smooth {111} facets. The gratings are patterned using interferometric lithography with 351.1 nm wavelength and transferred into the substrate using tri-level resist processing, reactive-ion etching (RIE), and silicon nitride masking during the KOH etch. The narrow ridge of silicon which supports the nitride mask is removed using a chromium lift-off step followed by a RIE trench etch. The result is a grating with extremely smooth blaze facets which is suitable for x-ray reflection after evaporative coating with thin Cr/Au. Atomic force microscope images confirm that fabricated gratings have less than a 0.4 nm rms roughness—much smoother than conventional gratings which have over roughness. Theory predicts that reduced blaze facet roughness increases diffraction efficiency. Experiments and simulations performed at the Lawrence Berkeley Laboratory and Columbia University confirm that efficiency is increased; in fact, measured peak efficiencies reach of calculated theoretical limits. Peak grating efficiencies were achieved that are greater than that of the best available ruled masters of comparable design.
Skip Nav Destination
Article navigation
November 1997
This content was originally published in
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena
Papers from the 41st international conference on electron, ion, and photon beam technology and nanofabrication
27-30 May 1997
Dana Point, California (USA)
Research Article|
November 01 1997
Super-smooth x-ray reflection grating fabrication
A. E. Franke;
A. E. Franke
Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Search for other works by this author on:
M. L. Schattenburg;
M. L. Schattenburg
Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Search for other works by this author on:
E. M. Gullikson;
E. M. Gullikson
Center for X-ray Optics, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
Search for other works by this author on:
J. Cottam;
J. Cottam
Department of Physics, Columbia University, New York, New York 10027
Search for other works by this author on:
S. M. Kahn;
S. M. Kahn
Department of Physics, Columbia University, New York, New York 10027
Search for other works by this author on:
A. Rasmussen
A. Rasmussen
Department of Physics, Columbia University, New York, New York 10027
Search for other works by this author on:
J. Vac. Sci. Technol. B 15, 2940–2945 (1997)
Article history
Received:
May 29 1997
Accepted:
July 21 1997
Citation
A. E. Franke, M. L. Schattenburg, E. M. Gullikson, J. Cottam, S. M. Kahn, A. Rasmussen; Super-smooth x-ray reflection grating fabrication. J. Vac. Sci. Technol. B 1 November 1997; 15 (6): 2940–2945. https://doi.org/10.1116/1.589759
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Pay-Per-View Access
$40.00
Citing articles via
Future of plasma etching for microelectronics: Challenges and opportunities
Gottlieb S. Oehrlein, Stephan M. Brandstadter, et al.
Novel low-temperature and high-flux hydrogen plasma source for extreme-ultraviolet lithography applications
A. S. Stodolna, T. W. Mechielsen, et al.
High-efficiency metalenses for zone-plate-array lithography
Henry I. Smith, Mark Mondol, et al.