Walter Scott, Jr. College of Engineering

Graduate Exam Abstract

Michael Grisham
M.S. Final
Jun 22, 2009, 8:30 am
ERC B301
Abstract: Compact high repetition rate Extreme Ultraviolet (EUV) lasers operating in the gain-saturated regime have opened the opportunity to conduct experiments with intense coherent EUV light on a table-top. This thesis discusses the use of a capillary discharge Ne-like Ar laser operating at 46.9 nm wavelength in the ablation of materials, nanopatterning, and high resolution imaging.
Unlike visible light, EUV light has a very shallow penetration in practically all materials. Also, its high photon energy allows single photons to break bonds in materials such as common polymers. These features result in ablation mechanisms that are different from those associated with lasers that operate at optical wavelenghts. This thesis studies EUV laser induced damage on three common organic polymers, metals, and Sc/Si multilayer coatings. As an application of the interactions of coherent EUV light with materials we have demonstrated the maskless printing of gratings with lines as small as 55 nm using interferometric lithography.
The short wavelength of the EUV lasers also offers the opportunity for improving the spatial resolution in imaging systems. This thesis describes the first implementantion of an EUV microscope capable of operating in transmission and reflection modes. The microscope combines a reflective optics condenser and a diffractive zone plate objective with the bright output from the 46.9 nm wavelength laser. Images were obtained with a spatial resolution of 120 – 150 nm. These results enabled subsequent experiments that have demonstrated single- shot imaging of nanostructures with 54 nm spatial resolution.

Michael Eric Grisham
Electrical and Computer Engineering Department
Colorado State University
Fort Collins, CO 80523
Summer 2009
Adviser: Jorge Rocca
Co-Adviser: none
Non-ECE Member: Elliot Bernstein Chemistry
Member 3: Carmen Menoni Electrical Engineering
Addional Members: none
Program of Study: