The Center for X-Ray Optics is a multi-disciplined research group within Lawrence Berkeley National Laboratory's (LBNL) Materials Sciences Division (MSD). Notice to users.
"We develop custom nanostructures and unique zone plates for a diverse set of collaborators worldwide. Our experienced team of scientists and engineers is here to push the limits of nanofabrication and diffractive lenses to help scientists realize the unique goals of their research in wide-ranging areas such as nano-diffractive optics, semiconductors, nano-magnetics, and nano-mechanics. When you find yourself in need of nanofabrication expertise for your research or development project, we are here to help."
Traditional refractive lenses don't work with x-ray and EUV light because absorption is too high. To bend and focus light at these wavelengths, optical systems must use reflective or diffractive lenses. The image to the left shows a diffractive 'zone plate' lens that was installed at the XM-1 microscope at the Advanced Light Source, enabling 15 nm spatial resolution. CXRO’s Nanowriter is the world’s only electron-beam lithography tool customized to create the curved, continuous shapes that define the zone plate pattern.
Using a double-exposure overlay technique, CXRO's Nanowriter team produced the world's highest resolution zone plate enabling imaging resolution of 12 nm.
CXRO's new website, zoneplate.lbl.gov, provides a full spectrum of information related to the theory, design, tolerancing, and fabrication of Fresnel zone plates. It is separated in to five main areas:
Diffraction gratings (below)
Zone plates (below)
Diffractive or holographic optical elements can play an important role in lithography systems by providing an efficient mechanism for generating modified illumination. CXRO's scientific team was the first to demonstrate and characterize an EUV binary phase-only computer-generated hologram allowing arbitrary far-field diffraction patterns to be generated. The device shown below achieved an absolute efficiency of 22% into one diffracted order.
SEM image of custom EUV phase-only holographic optical element (HOE) before multilayer deposition
SEM cross-seciton of Mo/Si multilayer coating on 2-nm-tall HOE features.
Far-field +1 order EUV diffraction pattern from the manufactured HOE.
Defects buried beneath the reflective multilayer coating can ruin EUV lithography masks. CXRO's Nanowriter is used to create customized, programmed defects for systematic defect detectability and printability studies.
SEM cross section of a programmed buried defect coated with a multilayer.
Templated block-copolymer self-assembly may be a great way to achieve dense patterned media with periods below 20 nm and with long range order over several cm. In collaboration with Seagate, the CXRO Nanowriter has been used to generate self-assembly templates for 0.5 Tb/in2 bit patterned media. Images courtesy of Kim Lee, Seagate.
SEM of 0.5 Tb/in2 pattern generation template
SEM of a servo pattern
The Nanowriter (below) supports a broad array of scientific instruments and projects worldwide. Its 8-nm beam size, conbined with its 2-nm overlay accuracy enables patterning of dense features down to 10 nm half-pitch.
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