AVS 61st International Symposium & Exhibition
    Accelerating Materials Discovery for Global Competitiveness Focus Topic Tuesday Sessions
       Session MG-TuA

Paper MG-TuA3
Monte Carlo Simulations of Nanoscale Focused Electron Beam Induced Etching

Tuesday, November 11, 2014, 3:00 pm, Room 302

Session: Multi-scale Modeling in the Discovery of Advanced Materials
Presenter: Philip Rack, The University of Tennessee Knoxville
Authors: R. Timilsina, The University of Tennessee Knoxville
P.D. Rack, The University of Tennessee Knoxville
K. Wolff, Carl Zeiss SMS, Germany
M. Budach, Carl Zeiss SMS, Germany
K. Edinger, Carl Zeiss SMS, Germany
Correspondent: Click to Email
Focused beam (electron-ion-photon) induced processing has long been utilized as a micro-/nano-scale direct synthesis method for both additive (via deposition) and subtractive (via etching) machining for a variety of editing and prototyping applications. Nanoscale lithography mask editing is one critical area which is pushing the limits for these beam induced processing methods. Beam damage associated with liquid gallium and the recently developed gas field ion source limits their utility in lithography mask repair due to the stringent optical requirements. Thus, electron beam induced processing for mask repair of both clear and opaque defects is the method of choice. To understand the fundamental electron-solid-precursor interactions, a Monte Carlo electron-solid simulation has been developed with a dynamic precursor gas routine which emulates adsorption/desorption, surface diffusion and electron stimulated reactions. The simulation was recently modified to handle electron beam induced etching. The electron beam induced etching of silicon dioxide is studied at low and high energies, short and long dwell times and various etch precursor gas conditions to elucidate important rate limiting regimes. Furthermore, the temporal behavior of the high-aspect ratio etch process is demonstrated. In this presentation we will overview the Monte Carlo simulation and will illustrate how various parameters affect the resolution and etch rate of the electron beam stimulated etch process. We will demonstrate how beam parameters (beam energy, current, and dwell and refresh time) precursor parameters (flux, residence time, surface diffusion coefficient, dissociation cross-section) and material (secondary electron yield, density) all contribute to the nanoscale etching process.