Effect of parasitic polytypes on ballistic electron transport in chemical vapor deposition grown 6H-SiC epitaxial layers
Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva, 8410501 Israel
Publication Date (Web): Jan 14, 2019
Copyright © 2018 VBRI Press
Growth of epitaxial layers is required for most of today’s devices. Epilayer growth is commonly carried out under conditions less optimal than those of bulk growth. In materials having multiple stable polytypes, such as SiC, it may facilitate concurrent nucleation of undesired polytypes. Using ballistic electron emission spectroscopy, we have repeatedly encountered a spectral feature in chemical vapor deposition (CVD) grown 6H-SiC layers that was absent in spectra of bulk material. This feature is suggested to belong to 4H-SiC inclusions. The presence of a concurrent Schottky barrier in our CVD epilayers coincides with an observation of a lower Fermi level pinning position compared with bulk material.
Silicon carbide, 6H-SiC, polytypes.