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Intellectual Property Office

Nanoscale Pattern Transfer for Lithography, Optics, Films and NEMS IB-2162

APPLICATIONS OF TECHNOLOGY:

  • Nanoscale pattern transfer for materials such as:
    • Molds made of silicon or metal
    • Polymer films
    • Metal printing press
    • Light-reflective films to cover windows in homes and cars
  • Patterning nanoscale features for the fabrication of:
    • Nanoresolution templates for nanoimprint lithography (NIL)
    • Nanodevices, e.g., nanoelectronics, nano-electro-mechanical systems (NEMS)
    • Nano-optics

ADVANTAGES:

  • More cost-effective than conventional techniques
  • Creates smoother sidewalls than current methods, with a roughness as low as 1 nm
  • Etches features as low as 10 nm for nanodevices that are less than 50 nm in diameter
  • Retains nanopatterns with features as small as 10 nm after transfer
  • Useful for deep or shallow etching of silicon or metals
  • Minimizes ion bombardment

ABSTRACT:

Deirdre Olynick and Weilun Chao of Berkeley Lab, and Ivo Rangelow of the University of IImenau, Germany, have developed a new dry etching process that alternates deposition and etching for producing and transferring nanoscale patterns in silicon, metals, or any materials that can be spontaneously etched in a fluorine-based chemistry. The new method, which offers a versatility at the nanoscale that previous methods have failed to achieve, can be used for either shallow or deep etching of thin films, metal molds, or silicon-based polymer films, or deep etching of metal, for example, to make zone plate lenses for X-ray or EUV (extreme ultraviolet) optical devices. It can also be used to etch nanofeatures for the fabrication of nanoresolution templates for nanoimprint lithography (NIL), nanodevices (e.g., nanoelectronics and nano-electro-mechanical systems [NEMS]), and nano-optics.

Current techniques are ineffective at the nanoscale because they produce ripples in the 10s of nm range; moreover, they make the transfer of nanofeatures in the sub-20 nm range nearly impossible due to the erosion of the silicon or metal being etched. The researchers have overcome these limitations by taking advantage of the radical chemistry or spontaneous etching that occurs when silicon or metals such as aluminum, molybdenum, titanium, and tungsten are etched with fluorine chemistries. Unlike the ion-driven process, the new nanoscale etching method allows features of various sizes to be etched with identical feature profiles on the same substrate.

The inventors have also discovered a method for combining inductively coupled plasmas with controlled fluorocarbon chemistry to produce sidewalls with roughnesses that can fall below 1 nm, making it ideal for etching features in the sub-10 nm regime for the fabrication of nanodevices such as nanoelectronics and NEMS, nano-optics, and nanoresolution templates for NIL. With its use of lower-cost gases (e.g., fluorocarbons), the new technique also promises to be more affordable and versatile than standard alternating etching methods.

STATUS:

To learn more about licensing a technology from LBNL see http://www.lbl.gov/Tech-Transfer/licensing/index.html.

FOR MORE INFORMATION:

Goodyear, A. L., Mackenzie, S., Olynick, D. L., Anderson, E. H., “High resolution inductively coupled plasma etching of 30 nm lines and spaces in tungsten and silicon,” J. Vac. Sci. Technol . B 18(6), Nov/Dec 2000, 3471-3475. Nanoscale anisotropic etching, nanoscale anisotropic metal etching, anisotropic silicon etching, dry nanoscale etching, nanopattern transfer, inductively coupled plasma, radical chemistry, spontaneous etching, zoneplate fabrication, nanoimprint technology, nanoimprint lithography, NIL, NEMS,

Olynick, D.L., Liddle, J. A., Harteneck, B. D., Cabrini S., Rangelow, I. W., “Nanoscale pattern transfer for templates, NEMS, and nano-optics,” Proceedings of SPIE 6462 (2007).

REFERENCE NUMBER: IB-2162

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