Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

Resist Mechanisms and Models in Electron-Beam Lithography

Nelson N.-S. Tam

EECS Department
University of California, Berkeley
Technical Report No. UCB/ERL M91/102
1991

http://www.eecs.berkeley.edu/Pubs/TechRpts/1991/ERL-91-102.pdf

An in-depth examination of chemical and physical mechanisms in resist materials has been made to support the applications of electron-beam (e-beam) lithography with high beam current exposure systems and advanced resist systems. Novel resist models and extensions to the lithography simulator SAMPLE have been developed to provide a CAD capability for inexpensive and rapid evaluation of new e-beam lithographic processes. Due to the small thermal conductivity of resists, e-beam induced heating of resists during exposure can be quite significant. Resist deformation and irregular dissolution behaviors have been observed in the RD-2000N resist when the beam current density exceeds 25 A/cm2. A massively parallel computer program using an explicit Euler algorithm has been developed to simulate the temperature rise in the resist during exposure as a function of pattern, tool and resist parameters. A novel approach of using empirically-modeled parameters in the mechanism-based rate model is introduced to include additional process variables. An application to developer concentration and post-exposure bake (PEB) makes possible profile simulation for the optimization of these processing steps in chemically-amplified resists.

Advisor: Andrew R. Neureuther


BibTeX citation:

@phdthesis{Tam:M91/102,
    Author = {Tam, Nelson N.-S.},
    Title = {Resist Mechanisms and Models in Electron-Beam Lithography},
    School = {EECS Department, University of California, Berkeley},
    Year = {1991},
    URL = {http://www.eecs.berkeley.edu/Pubs/TechRpts/1991/1878.html},
    Number = {UCB/ERL M91/102},
    Abstract = {An in-depth examination of chemical and physical mechanisms in resist
materials has been made to support the applications of electron-beam
(e-beam) lithography with high beam current exposure systems and
advanced resist systems. Novel resist models and extensions to
the lithography simulator SAMPLE have been developed to provide a
CAD capability for inexpensive and rapid evaluation of new e-beam
lithographic processes.

Due to the small thermal conductivity of resists, e-beam induced
heating of resists during exposure can be quite significant. Resist
deformation and irregular dissolution behaviors have been observed in
the RD-2000N resist when the beam current density exceeds 25 A/cm2. A
massively parallel computer program using an explicit Euler algorithm
has been developed to simulate the temperature rise in the resist
during exposure as a function of pattern, tool and resist parameters.

A novel approach of using empirically-modeled parameters in the
mechanism-based rate model is introduced to include additional
process variables. An application to developer concentration and
post-exposure bake (PEB) makes possible profile simulation for the
optimization of these processing steps in chemically-amplified
resists.}
}

EndNote citation:

%0 Thesis
%A Tam, Nelson N.-S.
%T Resist Mechanisms and Models in Electron-Beam Lithography
%I EECS Department, University of California, Berkeley
%D 1991
%@ UCB/ERL M91/102
%U http://www.eecs.berkeley.edu/Pubs/TechRpts/1991/1878.html
%F Tam:M91/102