A method for depositing a film on a substrate using a plasma enhanced
atomic layer deposition (PEALD) process includes disposing the substrate
in a process chamber configured to facilitate the PEALD process, wherein
the process chamber includes a substrate zone proximate the substrate and
a peripheral zone proximate to a peripheral edge of the substrate. Also
included is introducing a first process material within the process
chamber, introducing a second process material within the process chamber
and coupling electromagnetic power to the process chamber during
introduction of the second process material in order to generate a plasma
that facilitates a reduction reaction between the first and the second
process materials at a surface of the substrate. Electromagnetic power is
coupled to a process electrode to generate a substrate zone plasma in the
substrate zone that ionizes contaminants substantially in a region of the
substrate, and electromagnetic power to a peripheral electrode to
generate a peripheral zone plasma in the peripheral zone having a
characteristic different from the substrate zone plasma such that ionized
contaminants are transported from the substrate zone to the peripheral
zone in the process chamber.