Particle contamination in a variety of plasma processes and tools has
been studied using a real-time, in-situ detection technique, rastered
laser light scattering. In agreement with previous studies, particles
were suspended in the plasma. The distribution of particles, however,
is highly ordered and predictable, in contrast to the randomness which
typifies particulate behavior in uncharged environments, such as clea
nrooms. The importance of electrostatic particle trapping is seen, as
a means of understanding this ordered distribution of particles, for p
redictive performance of process tools in manufacturing, and for conta
mination control in processing tools. The implications of these result
s on future plasma processing is briefly discussed.