3C-SiC growth on Si substrates via CVD: An introduction - Mansic

Figure 3. Time vs. temperature graph of CVD process
4. Results and Characterizations
4.1. <strong>3C</strong>-<strong>SiC</strong> on Si hetero-defects
The defects formation in the <strong>3C</strong>-<strong>SiC</strong> layers grown by CVD on silicon is due to the
large lattice mismatch and the difference in thermal expansion coefficient
between Si and <strong>SiC</strong>. The Figure 4 illustrates the affect of the lattice mismatch at
the interface between the <strong>3C</strong>-<strong>SiC</strong> layers and the Si substrates.
Figure 4. Illustration of the affect of lattice mismatch in heteroepitaxy. The – symbol
denotes the location of a missing row of atoms which is known as a line defect.
Note the stretched and compressed covalent bonds at the interface resulting
from the lattice mismatch between the two crystals.
The most common defects in the <strong>3C</strong>-<strong>SiC</strong> layers are stacking faults (SFs),
microtwins (MTs) and anti-phase boundaries (APBs).
4.2. X-ray diffraction (XRD)
4.2.1. Powder diffraction
The crystalline quality of the grown layers is analyzed by x-rays diffraction in
Bragg-Brentano mode with Cu-Kα monochromatic source. In the Figure 5, XRD
spectra of <strong>SiC</strong> layers grown on Si (001) substrates with different <strong>growth</strong> rates of
Physics of Advanced Materials Winter School 2008 4