Microscopic Investigation of SiC Epitaxial Layers οn On-Axis 4H-SiC Substrates Using Kelvin Probe Force Microscopy
K. Kościewicz a, b, R. Bożek c, W. Strupiński b and A. Olszyna a
a Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw, Poland
b Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw, Poland
c Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, 00-681 Warsaw
Full Text PDF
We report on Kelvin probe force microscopy and electron backscatter diffraction measurements of 3C-SiC epitaxial layers grown on exactly oriented Si-face 4H-SiC (0001) substrates in a horizontal hot-wall chemical vapor deposition reactor, in the temperature range from 1150°C to 1620°C, under H2 or H2 +SiH4 atmosphere. The investigated layers were doped with nitrogen (for n-type) and aluminium (for p-type). The electron backscatter diffraction analysis revealed structure of polytype 3C blocks with a relative rotation of 60 and/or 120°. The Kelvin probe force microscopy measurements revealed cubic substructure as a equilateral triangle objects contrast which is characteristic of 3C silicon carbide polytype. The surface potential contrast was found to be dependent on the type and concentration of doping, which could be explained in terms of the impurities accumulation at block boundaries.
DOI: 10.12693/APhysPolA.116.S-69
PACS numbers: 68.35.bg, 81.15.-z, 34.20.-b, 61.05.J-