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Title: Polycrystalline silicon carbide dopant profiles obtained through a scanning nano-Schottky contact

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4957177· OSTI ID:22597859
; ;  [1];  [2]
  1. U.S. Army Research Laboratory, WMRD, Aberdeen Proving Ground, Maryland 21005 (United States)
  2. ORISE, Belcamp, Maryland 21017 (United States)

The unique thermo-electro-mechanical properties of polycrystalline silicon carbide (poly-SiC) make it a desirable candidate for structural and electronic materials for operation in extreme environments. Necessitated by the need to understand how processing additives influence poly-SiC structure and electrical properties, the distribution of lattice defects and impurities across a specimen of hot-pressed 6H poly-SiC processed with p-type additives was visualized with high spatial resolution using a conductive atomic force microscopy approach in which a contact forming a nano-Schottky interface is scanned across the sample. The results reveal very intricate structures within poly-SiC, with each grain having a complex core-rim structure. This complexity results from the influence the additives have on the evolution of the microstructure during processing. It was found that the highest conductivities localized at rims as well as at the interface between the rim and the core. The conductivity of the cores is less than the conductivity of the rims due to a lower concentration of dopant. Analysis of the observed conductivities and current-voltage curves is presented in the context of nano-Schottky contact regimes where the conventional understanding of charge transport to diode operation is no longer valid.

OSTI ID:
22597859
Journal Information:
Journal of Applied Physics, Vol. 120, Issue 2; Other Information: (c) 2016 U.S. Government; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English