Accession Number : ADA325121

Title :   Electrical Characterization of Intrinsic and Induced Deep Level Defects in Hexagonal SiC.

Descriptive Note : Doctoral thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Scofield, James D.

PDF Url : ADA325121

Report Date : DEC 1996

Pagination or Media Count : 394

Abstract : Deep level defects in hexagonal SiC were studied using digital deep level transient spectroscopy (DLTS) methods over the temperature range of 100 to 800 deg K. New centers were found in bulk and epitaxial 6H-SiC with ionization energies between 0.38 to 1.3 eV, and levels from 0.2 to 0.856 eV were identified in 4H-SiC epitaxy. Direct correlation between inequivalent lattice sites was identified for energetic pairs associated with both vanadium and ion implanted Mg impurities. Nonradioative carrier capture mechanisms were studied and deep level trapping was found to proceed via lattice relaxation multi-phonon emission, indicating efficient electronic lattice coupling in the wide bandgap material. Junction transport characteristics of 4H-SiC p+/n bipolar devices were observed to be dominated by deep level defects in the epitaxial layers. Significant tunneling conduction in both forward and reverse bias conditions was directly correlated to deep level centers in these devices.

Descriptors :   *DEFECTS(MATERIALS), *THERMAL CONDUCTIVITY, *SILICON CARBIDES, MAGNESIUM, THESES, ENERGY GAPS, EPITAXIAL GROWTH, IONIZATION, JUNCTIONS, LUMINESCENCE, TEMPERATURE COEFFICIENTS, VANADIUM.

Subject Categories : Electricity and Magnetism
      Solid State Physics
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE