A comparative investigation on the effects of
sacrificial oxidation (SO) on the surface properties of n- and p-type 4H-SiC
has been conducted by using x-ray photoelectron spectroscopy and deep level
transient spectroscopy. For n-type 4H-SiC, the surface Fermi level is unpinned
and shifts towards conduction band edge due to significant reduction of surface
contaminants and removal of surface defects by SO. For p-type 4H-SiC, the
surface contamination is also reduced with a shift of Fermi level towards
valance band edge after SO. However, a high density of carbon interstitials
related defects is likely to be generated close to the valance band during the
oxidation. Pronounced Fermi level pinning may be still present with surface
states density higher than 1.65 × 1012 cm−2 eV−1. The implications of SO on the
electrical behaviors of metal contacts to n- and p-type 4H-SiC have been
proposed.
Source:IOPscience
For more information, please visit our website:
send us email at sales@powerwaywafer.com and powerwaymaterial@gmail.com
No comments:
Post a Comment