The effect of ion beams on the formation of Si nanoclusters from
a-SiOx films and their luminescence
properties is investigated. a-SiOx films with Si
content ranging from 33 to 50 at. % were deposited by Electron Cyclotron
Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD) of
SiH4 and O2. Prior to anneal, some samples were
implanted with 380 keV Si to a dose ranging from 5.7 × 1014
cm−2 to 5.7 × 1016 cm−2. All films were
rapid thermal annealed under flowing Ar environment, and hydrogenated after
anneals to passivate defects and to enhance the luminescence of Si
nanoclusters. For films with Si content less than 40 at. %, ion beam
slightly reduces the photoluminescence (PL) intensity and induces a slight
blueshift of the luminescence. For films with Si content greater than 40 at.
%, ion beam greatly increases the PL intensity. Based on the effect of the
ion beams dose and the ion specie, we propose that ion beams damage greatly
promotes nucleation of small Si clusters from the
a-SiOx matrix.