Finite silicon atom diffusion induced size limitation on self-assembled silicon quantum dots in silicon-rich silicon carbide
Journal
Journal of the Electrochemical Society
Journal Volume
159
Journal Issue
2
Pages
K35-K41
Date Issued
2012
Author(s)
Abstract
Finite Si atom diffusion induced size limitation of self-assembled Si quantum dots (Si-QDs) in silicon-rich silicon carbide (SiC) is demonstrated. After annealing, the Si-QDs with a size of 3 ± 1 nm are precipitated in the matrix of SiC 0.51 deposited by low-temperature plasma-enhanced chemical vapor deposition with Argon-diluted silane and methane mixture. The amorphous-Si dependent Raman scattering peak at ∼470 cm -1 is narrowing with increasing temperature, and the Si-CH 3 rocking-mode absorption line is shifted by dehydrogenation after high-temperature treatment. The self-assembled Si-QDs in SiC 0.51 with a volume density of 4.4 × 10 18 cm -3 transfer from amorphous to crystalline phase by increasing annealing temperature from 850°C to 1050°C. The calculated Si atom diffusion coefficient of 3-4 × 10 -4 nm 2+ s -1 in Si-rich SiC 0.51 is 7 orders of magnitude larger than that in pure SiC, which coincides with the linear extrapolation from pure Si and SiC and reveals nonlinear proportionality with CSi composition ratio and Si-QD size. © 2011 The Electrochemical Society.
Type
journal article