Silicon Carbide Substrates for GaN Research and Development
Final technical rept. 29 Jul 2000-30 Jun 2001
CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF MATERIALS SCIENCE AND ENGINEERING
Pagination or Media Count:
6H-SiC boules have been grown by physical vapor transport PVT method and analyzed using mass spectroscopy glow discharge and secondary ion and transport methods. The dominant impurities in crystals grown from commercial SiC charge are nitrogen and boron. Nitrogen concentrations decrease toward the tail while that of boron and aluminum increase. The Fermi level in all crystals started at being pinned to nitrogen donor level in the seed end of the boule and dropped to the shallow boron acceptor level at the tail end. The middle part exhibited either a narrow or wide band of high-resistivity material, depending primarily on the impurity content and segregation. The transition metals have a low incorporation coefficient in 6H-SiC and even in intentionally doped crystals were below mass spectroscopy detection limit.
- Inorganic Chemistry
- Solid State Physics