Radiotracer investigation of deep Ga- and Zn-related band gap states in 6H-SiC

To identify Ga- or Zn-related deep levels, deep level transient spectroscop y (DLTS) measurements were performed repeatedly during the elemental transm utation of Ga-67 to Zn-67. The radioactive isotope Ga-67 was recoil implant ed into p-type 6H-SiC for radiotracer experiments. The DLTS spectra exhibit one peak of time-dependent height. It describes the increasing concentrati on of the daughter element Zn with the half life of the nuclear decay. Thus , one Zn-related level at 1.16 eV above the valence band edge is definitely identified. There is no deep level of Ga in the lower part of the band gap . (C) 1998 American Institute of Physics. [S0003-6951(98)02551-0].