Newsgroups: sci.physics.plasma
From: mike@hansa.CChem.Berkeley.EDU (mike kilgore)
Organization: University of California, Berkeley
Subject: Re: Dusty Plasmas

doniger@cimd20.cam (Ken Doniger) writes:

:I am interested in particulate formation in plasma-using semiconductor
:processing equipment (etchers, sputterers). Can anyone suggest recent
:journals or a book?
:Thank you.

I have worked on dusty materials processing plasmas as part of my PhD
thesis work. Here are a few references which could serve as a starting
point for you.

Two compilations of recent work:

IEEE TRANSACTIONS ON PLASMA SCIENCE, 1994 APR, V22 N2
(special issue with many papers on dusty processing plasmas)

Plasma Sources Science and Technology, 1994 vol. ?
(special section with Proceedings from last year's Conference
on the Creation, Transport, and Consequences of Particles
in Plasmas - NATO Advanced Research Workshop... this volume
should be out soon)

Some relevant publications from my group:

M.D. Kilgore, J.E. Daugherty, R. K. Porteous, and D. B. Graves, Transport and
Heating of Small Particles in High Density Plasma Sources, Journal of Vacuum
Science and Technology B 12 (1), 486, (1994).

D. B. Graves, M. D. Kilgore, J. E. Daugherty and R. K. Porteous, A Model of
Particulates in Glow Discharge Plasmas, Proceedings of the Ninth Symposium
on Plasma Processing, ed. by G.S. Mathad and D.W. Hess, Proceedings of the
Electrochemical Society 92-18, 221 (1992).

M.D. Kilgore, J.E. Daugherty, R. K. Porteous, and D. B. Graves, Ion Drag on an
Isolated Particulate in a Low Pressure Discharge, Journal of Applied Physics, 73,
7195, (1993).

J. E. Daugherty, R. K. Porteous, M. D. Kilgore, and D. B. Graves, Sheath
Structure Around Particles in Low Pressure Discharges, Journal of Applied
Physics, 72 (9), (1992).


Our group's work deals mainly with applying the fundamental physics of dusty
plasmas to understand the transport behavior of particles in materials
processing plasmas. We haven't attempted to describe particle formation
mechanisms in any detail. If you are interested in the actual formation
mechanisms, then I recommend the above-mentioned upcoming issue of Plasma
Sources Science and Technology. Included there are some good papers
describing particulate formation in silane-argon deposition plasmas. Particle
formation in etching and sputtering systems has been observed (see references
in papers from our group), but IMHO the actual formation mechanisms may
be less well understood than for the silane-argon deposition plasmas.
Particulates may arise from gas-phase growth or from heterogeneous processes
at walls. Therefore, different reactors, chemistries, operating conditions,
etc. may produce particulates by a variety of mechanisms. Our
philosophy has been that we are mainly concerned with keeping particulates
from contaminating wafers, so we have side-stepped some of the tough issues
about formation and have focused on the transport behavior of particulates.
We have proceeded to work to understand how the plasma processing equipment
and operating conditions can be tailored to avoid device yield loss from the
process generated particulates.

Let me know if I can be of further assistance. This research area is much
too big to describe adequately here!

Good luck...Mike Kilgore