Accession Number : ADA593998


Title :   Compensation Mechanism in High Purity Semi-Insulating 4H-SiC


Descriptive Note : Journal article


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC


Personal Author(s) : Mitchel, W C ; Mitchell, William D ; Smith, H E ; Landis, G ; Smith, S R ; Glaser, E R


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA593998


Report Date : Jan 2007


Pagination or Media Count : 8


Abstract : A study of deep levels in high purity semi-insulating 4H-SiC has been made using temperature dependent Hall effect (TDH), thermal and optical admittance spectroscopies, and secondary ion mass spectrometry (SIMS). Thermal activation energies from TDH varied from a low of 0.55 eV to a high of 1.65 eV. All samples studied showed n-type conduction with the Fermi level in the upper half of the band gap. Fits of the TDH data to different charge balance equations and comparison of the fitting results with SIMS measurements indicated that the deep levels are acceptor like even though they are in the upper half of the band gap. Carrier concentration measurements indicated that the deep levels are present in concentrations in the low 10(15) cm( 3) range, while SIMS results demonstrate nitrogen and boron concentrations in the low to mid-10(15)-cm( 3) range. The results suggest that compensation in this material is a complex process involving multiple deep levels.


Descriptors :   *COMPENSATION , *PURITY , ACTIVATION ENERGY , BAND GAPS , BORON , EQUATIONS , FERMI SURFACES , MASS SPECTROMETRY , NITROGEN , OPTICAL PROPERTIES , SPECTROSCOPY , THERMAL PROPERTIES


Subject Categories : Physical Chemistry
      Operations Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE