A planar refractive x-ray lens made of nanocrystalline diamond (original) (raw)

Nanofocusing optics for synchrotron radiation made from polycrystalline diamond

Optics Express, 2014

Diamond possesses many extreme properties that make it an ideal material for fabricating nanofocusing x-ray optics. Refractive lenses made from diamond are able to focus x-ray radiation with high efficiency but without compromising the brilliance of the beam. Electron-beam lithography and deep reactive-ion etching of silicon substrates have been used in a transfer-molding technique to fabricate diamond optics with vertical and smooth sidewalls. Latest generation compound refractive lenses have seen an improvement in the quality and uniformity of the optical structures, resulting in an increase in their focusing ability. Synchrotron beamline tests of two recent lens arrays, corresponding to two different diamond morphologies, are described. Focal line-widths down to 210 nm, using a nanocrystalline diamond lens array and a beam energy of E = 11 keV, and 230 nm, using a microcrystalline diamond lens at E = 15 keV, have been measured using the Diamond Light Source Ltd. B16 beamline. This focusing prowess is combined with relatively high transmission through the lenses compared with silicon refractive designs and other diffractive optics.

Diamond planar refractive lenses for third- and fourth-generation X-ray sources

Journal of Synchrotron Radiation, 2003

The fabrication and testing of planar refractive hard X-ray lenses made from bulk CVD diamond substrates is reported. The lens structures were generated by electron-beam lithography and transferred by reactive-ion etching into the diamond. Various lens designs were fabricated and tested at 12.4 and 17.5 keV photon energy. Ef®ciencies of up to 71% and gains of up to 26 were achieved. A line focus of 3.2 mm (FWHM) was measured. These lenses should be able to withstand the extreme¯ux densities expected at the planned fourth-generation X-ray sources.

Deep reactive ion etching of silicon moulds for the fabrication of diamond x-ray focusing lenses

Journal of Micromechanics and Microengineering, 2013

Diamond is a highly desirable material for use in x-ray optics and instrumentation. However, due to its extreme hardness and resistance to chemical attack, diamond is difficult to form into a structure suitable for x-ray lenses. Refractive lenses are capable of delivering x-ray beams with nanoscale resolution. A moulding technique for the fabrication of diamond lenses is reported. High-quality silicon moulds were made using photolithography and deep reactive ion etching. The study of the etch process conducted to achieve silicon moulds with vertical sidewalls and minimal surface roughness is discussed. Issues experienced when attempting to deposit diamond into a high-aspect-ratio mould by chemical vapour deposition are highlighted. Two generations of lenses have been successfully fabricated using this transfer-moulding approach with significant improvement in the quality and performance of the optics observed in the second iteration. Testing of the diamond x-ray optics on the Diamond Light Source Ltd synchrotron B16 beamline has yielded a line focus of sub-micrometre width.

Diamond kinoform hard X-ray refractive lenses: design, nanofabrication and testing

Journal of Synchrotron Radiation, 2008

Motivated by the anticipated advantageous performance of diamond kinoform refractive lenses for synchrotron X-ray radiation studies, this report focuses on progress in designing, nanofabricating and testing of their focusing performance. The method involves using lift-off and plasma etching to reproduce a planar definition of numerically determined kinoform refractive optics. Tests of the focusing action of a diamond kinoform refractive lens at the APS 8-ID-I beamline demonstrate angular control of the focal spot.

Fabrication of polycrystalline diamond refractive X-ray lens by femtosecond laser processing

Applied Physics A, 2016

X-ray planar compound refractive lenses were fabricated from a polycrystalline diamond plate grown by chemical vapor deposition, by precise through cutting with femtosecond laser pulses. The lens geometry and the surface morphology were investigated with optical and scanning electron microscopy, while the material structure modification was analyzed by Raman spectroscopy. The results of the preliminary lens test at 9.25-keV X-rays are presented.

Diamond crystal X-ray optics for high-power-density synchrotron radiation beams

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1993

Man-made perfect single crystal isotopically-enriched diamond is demonstrated to be an excellent X-ray monochromator even when subjected to the highest incident power density expected at third-generation synchrotron source undulator beam lines. Double-crystal rocking curve tests of a diamond (400) wafer exposed to an X-ray power density of 207 W/mmz (75 W total power) revealed just 1 arc sec of induced thermal distortion integrated across the beam footprint.

Nanofocusing parabolic refractive x-ray lenses

Applied Physics Letters, 2003

Parabolic refractive x-ray lenses with short focal distance can generate intensive hard x-ray microbeams with lateral extensions in the 100 nm range even at a short distance from a synchrotron radiation source. We have fabricated planar parabolic lenses made of silicon that have a focal distance in the range of a few millimeters at hard x-ray energies. In a crossed geometry, two lenses were used to generate a microbeam with a lateral size of 380 nm by 210 nm at 25 keV in a distance of 42 m from the synchrotron radiation source. Using diamond as the lens material, microbeams with a lateral size down to 20 nm and below are conceivable in the energy range from 10 to 100 keV.

Atomic layer deposition frequency-multiplied Fresnel zone plates for hard x-rays focusing

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films

The design and fabrication of Fresnel zone plates (FZPs) for hard X-ray focusing up to 25 keV photon energies with better than 50 nm imaging resolution is reported as performed by forming an ultra-nanocrystalline diamond (UNCD) scaffold, subsequently coating it with atomic layer deposition (ALD) with an absorber/phase shifting material, followed by back side etching of Si to form a diamond membrane device. The scaffold is formed by chemical vapor-deposited UNCD, electron beam lithography and deep-reactive ion etching of diamond to desired specifications. The benefits of using diamond are: improved 2 mechanical robustness to prevent collapse of high-aspect-ratio ring structures, a known high-aspect-ratio etch method, excellent radiation hardness, extremely low X-ray absorption, and significantly improved thermal/dimensional stability as compared to alternative materials. Central to the technology is the high-resolution patterning of diamond membranes at wafer scale, which was pushed to 60 nm lines and spaces etched 2.2-mdeep, to an aspect ratio of 36:1. The absorber growth was achieved by atomic layer deposition (ALD) of Ir, Pt or W, while wafer-level processing allowed to obtain up to 121 device chips per 4" wafer with yields better than 60%. X-ray tests with such zone plates allowed resolving 50 nm lines and spaces, at the limit of the available resolution test structures.

Development of nanocrystalline diamond windows for application in synchrotron beamlines

Vacuum, 2013

A multistep growth and masking method allowed developing windows with controlled geometry inside a silicon frame. In this paper, we present a new method to produce nanocrystalline diamond windows with thickness of about 200 nm to 40 mm, with different areas and shapes (circular, rectangular and rounded rectangle). The nanocrystalline diamond (NCD) films deposited on a silicon substrate (100) ptype, had a nucleation density of about 10 11 part/cm 2. Electrostatic self-assembly of nanodiamond seeds (4 nm powder) improved nucleation. Silicon anisotropic etching reveals the window geometry. The high nucleation density enabled smooth surfaces on both sides without the need for polishing the window. Pressure tests were performed in windows of varying thickness. The windows with thickness larger than 10 mm supported a pressure gradient of 1 atm.