Temperature dependence of electrical properties of non-doped and nitrogen-doped beta-SiC single crystals grown by chemical vapor deposition

Abstract

Electrical properties of non-doped and nitrogen-doped n-type β-SiC films grown on Si substrates have been investigated at 70–1000 K. Those of non-doped films remarkably depend on the Si/C ratio of the source gases. The highest mobilities of non-doped films are 510 and 1330 cm2 V−1 s−1 at 296 and 71 K, respectively. The carrier concentrations are as low as 6×1016 cm−3 even at 1000 K. Ionization energies of 34 –37 meV for nitrogen donors and 19–25 meV for unknown donors of non-doped films are obtained. Mobilities of both non-doped and nitrogen-doped films are dominated by lattice scattering at high temperatures and by impurity scattering at low temperatures. Nitrogen donors strongly affect the impurity scattering.