Lawrence Berkeley National Laboratory

Nanofabrication

CXRO’s nanofabrication group develops challenging nanofabrication processes and manufactures custom nanostructures for a diverse set of x-ray and EUV applications worldwide. With over three decades of experience, the team pushes the limits of electron-beam lithography and nanofabrication processes to produce world-class diffractive optics, EUV mask test patterns, nanostructured calibration standards, and custom devices. Our advanced zone plates are used at synchrotrons worldwide to deliver engineered beam profiles for EUV, soft and tender X-ray microscopy.

Sample Work

SEM of a composite zone plate generating two orbital angular momentum beams and one gaussian beam
SEM of a composite zone plate generating two orbital angular momentum beams and one gaussian beam.
SEM of a randomized probe illumination zone plate for soft x-ray microscopy
SEM of a randomized probe illumination zone plate for soft x-ray microscopy.
SEM of a 20:1 aspect ratio soft x-ray zone plate
SEM of a 20:1 aspect ratio soft x-ray zone plate
Cross section view of a EUV phase mask structure
Cross section view of a EUV phase mask structure

Facility Capabilities

Electron-Beam Lithography

An ultra high-resolution e-beam writer with sub-5 nm placement accuracy for fabricating zone plates, gratings, coded apertures, and EUV mask test patterns. The system supports small substrates and wafers up to 8” diameter.

Diffractive Optics

CXRO fabricates zone plates with outermost zone widths close to 10 nm, enabling spatial resolution at the leading edge of X-ray microscopy. Zone plates are produced in molybdenum, ruthenium, nickel, gold, and other high-Z materials. Typical substrates are custom-designed thin membrane windows.

Thin-Film Deposition & Etching

Sputter deposition, evaporation, atomic layer deposition, and reactive-ion etching systems for fabricating multilayer structures, hard masks, and freestanding membrane windows.

Custom Nanostructures

Beyond optics, the group fabricates custom nanostructured samples for microelectronics, EUV mask research, nanomagnetism, coherent scattering experiments, and calibration standards, including patterned media, photonic crystals, and programmed defects.

EUV & Soft X-ray Characterization

We have access to material and optical characterization at the Advanced Light Source beamlines for the optics and nanostructures we produce, including diffraction efficiency and wavefront measurements.

Nanofab Lab Equipment & Materials

Processing Equipment Examples

  • •Resist spin/bake
  • •Contact aligner
  • •E-beam evaporator
  • •Scanning Electron Microscope (SEM)
  • •Ni, Au, & Cu electroplating
  • •Dry etch ICP/RIE (Oxford Plasmalab & Samco)
  • •Molecular Foundry cleanroom

Supported Material Examples

Si, Si₃N₄, Mo, Ru, Au, Ni, Cr, Pt, Pd, Ge, Ti, Al, sapphire, and quartz

Oxford Plasmalab 100 dual-chamber ICP/RIE in the CXRO nanofabrication lab
Oxford Plasmalab 100 dual-chamber ICP/RIE in the CXRO nanofabrication lab.
Scanning electron microscope (SEM) used for process development and quality control
Scanning electron microscope (SEM) used for process development and quality control.

Zone Plate Specifications

Outermost Zone Width12–50 nm (standard); custom available
Diameter50–1000 μm
MaterialsGold, nickel, silicon, molybdenum, ruthenium on Si₃N₄ membranes
Energy Range20–2000 eV
Diffraction Efficiency5–20% (first order, energy dependent)

Related Research

Zone plates support X-Ray Microscopy & Imaging and EUV Photomask Imaging. Custom nanostructures are used in Nanomagnetism and Microelectronics research. Learn more at the Fresnel Zone Plate Education site.

Nanofabrication Team

Sarath Samudrala

Engineer

Weilun Chao

Staff Scientist