Laser Polishing/Planarization Process
Daryush Aidun's research objectives are to design and develop an
alternative method to CMP that is an optical process for the polishing
and/or planarization of wafers.
In an attempt
to accomplish this objective, he is investigating the use of excimer
lasers to remove materials by breaking their chemical bonds and
vaporizing them. The first and most important part of this research
is to determine the feasibility and the practicality of a laser
polishing/planarization (LPP) process. The next step is to make
conceptual designs of the LPP processes and to finally construct
a "prototype" process using the excimer lasers to polish silicon
wafers. Professor Aidun is currently modeling various aspects of
this work with collaborators CAMP Professor Cetinkaya and Mr. Postgate.
The advantages of such a process are its lower cost, higher productivity,
and its friendliness to the environment.
Professor Aidun and a group of students ( Michael P. Kozar, Luke
Simmons, John Ingraham, Anne Peairs, Matt Braun, and Matt Vogel),
in Professor Eric Thacher's Integrated Design course at Clarkson
University, are carrying out a welding design project. They are
designing and developing an automated dual-head arc welding process
with a built-in weld fume exhaust system. This unique process, which
is environmentally friendly, will increase efficiency and productivity.
Dr. Dana Barry Serves as Visiting Professor in Japan
the month of August, CAMP Editor and Technical Writer Dr. Dana
Barry served as a Visiting Professor at Suzuka National College
of Technology (SNCT) in Japan. She presented college lectures,
which aired on television in Japan, about Chemical-Mechanical
Polishing and her World First Space Missions. She also gave
Science Sensation and Faculty Development Seminars. In addition,
she taught chemistry classes at Takada High School in Japan
using an innovative method which incorporates music and science
experiments to present and reinforce concepts. Dr. Barry developed
this unique method in collaboration with Professor Hideyuki
Kanematsu of the Department of Materials Science and Engineering
at Suzuka. Other Suzuka professors working on this project are
Tatsumasa Kobayashi and Hiroshi Shimofuruya. This project is
sponsored by Suzuka National College of Technology and the Northern
New York Section of the American Chemical Society. Dr. Barry
is preparing a feature article about this international effort
for the January 2003 issue of the Japanese chemistry research
journal the Bulletin of the Tokai Kagaku Kougyoukai (The Society
of Midland Chemical Industries). Dr. Barry, a certified professional
chemist and external professor for Ansted University in Malaysia,
has over 80 professional publications and many honors and awards
to her name.
Laser-Based Nanoparticle Removal and Nanoadhesion Measurements
Professor Cetin Cetinkaya and his group have been conducting
analytical, computational and experimental work in the area of laser-
based particle removal and noncontact nanoadhesion measurement. There
is an immense need in various industries for dry removal of submicron
particles from substrates and trenches. Professor Cetinkaya's group has
developed a novel dry cleaning method to remove micron and submicron particles.
The new technique, based on laser-induced plasma shock waves, is a noncontact
method and the removal efficiency is an order of magnitude higher than
the traditional laser cleaning methods. This work involved a surface that
was polished copper with gold plating. The dry laser cleaning method is
being used to remove micron and submicron particles from varying substrates
as well as from micro-holes and semiconductor trenches. The new cleaning
method has demonstrated a great potential in the area of nanoparticle
removal. Various applications of this technology are being investigated
by Professor Cetinkaya's group. A recent National Science Foundation grant
entitled "Exploring the Limits of Nanoparticle Removal with Pulsed Lasers"
was awarded for this research.
of the Chemical-Mechanical Polishing Process
Ahmadi and his group are developing a model (based on mechanical contact
theory) for the chemical-mechanical polishing process. The goal of their
research is to provide a fundamental understanding of the parameters that
control the effectiveness of CMP for surface planarization. Their current
work focuses on the abrasive particle, wafer, and pad contact and the
abrasive and adhesive wear mechanisms in the chemical-mechanical polishing
process. They are developing a model for interactions of pad asperities
with abrasive particles and the wafer. Their analysis includes the influence
of abrasive particle adhesion to the surface of the wafer. Also they are
looking at the CMP process using hard and soft pads and dilute and concentrated
slurries. In addition Professor Ahmadi and his students are studying the
effect of abrasive particle shapes, slurry pH, and colloidal forces on
the removal rate.
model predictions are described in detail and compared with the available
semi-empirical correlations in the paper " A Model for Mechanical Wear
and Abrasive Particle Adhesion During the Chemical-Mechanical Polishing
Process," by G. Ahmadi and X. Xia, Journal of the Electrochemical Society
, 148 (3) G99-G109 (2001).