Uniformity of silicon microcrystallinity in large area RF capacitive reactors

Abstract

AbstractIn this work, a controlled, nonuniform RF power distribution is produced across a large area PECVD reactor. The effect of the RF power distribution on the crystallinity of silicon thin films deposited from silane‐hydrogen discharges is studied. Results show that, even with a strongly nonuniform RF distribution (70%), uniform crystallinity can still be achieved for films deposited at the limit between amorphous and microcrystalline silicon provided that the input silane concentration is sufficiently low (nominal concentration lower than ≈︂1˙2%). This work shows that to deposit silicon with a uniform microcrystallinity over large area using high silane concentration, the reactor design must guarantee a highly uniform power distribution. Copyright © 2008 John Wiley & Sons, Ltd.