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.