Spectroscopic phonon and extended x-ray absorption fine structure measurements on 3C-SiC/Si (001) epifilms
Journal
Applied Surface Science
Journal Volume
427
Pages
302-310
Date Issued
2018
Author(s)
Abstract
Comprehensive experimental and theoretical studies are reported to assess the vibrational and structural properties of 3C-SiC/Si (001) epilayers grown by chemical vapor deposition in a vertical reactor configuration. While the phonon features are evaluated using high resolution infrared reflectance (IRR) and Raman scattering spectroscopy (RSS) – the local inter-atomic structure is appraised by synchrotron radiation extended x-ray absorption fine structure (SR-EXAFS) method. Unlike others, our RSS results in the near backscattering geometry revealed markedly indistinctive longitudinal- and transverse-optical phonons in 3C-SiC epifilms of thickness d < 0.4 μm. The estimated average value of biaxial stress is found to be an order of magnitude smaller while the strains are two-orders of magnitude lower than the lattice misfits between 3C-SiC and Si bulk crystals. Bruggeman's effective medium theory is utilized to explain the observed atypical IRR spectra in 3C-SiC/Si (001) epifilms. High density intrinsic defects present in films and/or epilayer/substrate interface are likely to be responsible for (a) releasing misfit stress/strains, (b) triggering atypical features in IRR spectra, and (c) affecting observed local structural traits in SR-EXAFS. © 2017 Elsevier B.V.
Subjects
Brugeeman's effective medium theory; Chemical vapor deposition; Infrared reflectivity; Raman scattering spectroscopy; Synchrotron radiation x-ray absorption fine structure
Other Subjects
Absorption spectra; Absorption spectroscopy; Atomic physics; Chemical vapor deposition; Crystal atomic structure; Epilayers; Extended X ray absorption fine structure spectroscopy; Interfaces (materials); Phonons; Raman scattering; Reflection; Seismic waves; Synchrotron radiation; Synchrotrons; X ray absorption; Effective medium theories; Extended X-ray absorption fine structure measurements; Extended X-ray absorption fine structures; High resolution infrared; Infrared reflectivity; Raman scattering spectroscopy; Synchrotron radiation x-rays; Transverse optical phonons; Silicon carbide
Type
journal article