Fabrication of Nanostructures by Low Voltage Electron Beam Lithography

• Author / Creator

  Adeyenuwo, Adegboyega P.

• Electron Beam Lithography (EBL) is a powerful tool for structuring materials at the deep nanoscale. Modeling and simulation of electron-beam interactions at this length scale is vital to understanding and optimizing nanofabrication using EBL. The low to high voltage (5 keV – 100 keV) regimes of EBL have been studied for decades. However, the ultra-low regime (< 5 keV) provides an opportunity to further rationalize the understanding of this powerful technique and explore its applications. The ultra-low voltage regime was studied using (poly) methyl- methacrylate (PMMA) as the resist, and important metrics at this regime such as dose windows, exposure sensitivity and dose variation with exposure energy are explored. An application of low voltage EBL is presented to develop a process for pattern density multiplication in a single step. Density multiplication was demonstrated for arrays of nanostructures using a combination of experiments and simulation. This approach increased the areal density of the lithographically patterned lines by a factor of approximately 2 for dots and lines in a single exposure and development step. This application is not only interesting from a technological perspective, but also demonstrates the power of a combined experimental and simulation optimization strategy.

• Subjects / Keywords

  • Negative-tone tone resist
  • Density multiplication
  • Electron beam lithography
  • Model of development
  • Cold development
  • Positive-tone tone resist
  • Nanostructures
  • E-beam
  • Monte carlo simulation
  • Model of exposure of PMMA
  • Electron beam lithography simulator
  • Density multiplication of nanostructures
  • Fragmentation of PMMA
  • Lithography
  • Polymethylmethacrylate
  • Nanofabrication
  • PMMA
  • EBL

• Graduation date

  Spring 2012

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3BC7D

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.