On the high curvature coefficient rectifying behavior of nanocrystalline diamond heterojunctions to 4H-SiC.

Heterojunctions of p+ B-doped nanocrystalline diamond (NCD) to n- 4H-SiC were studied by electrical and cathodoluminescence (CL) methods. Current rectification at 30 °C had a curvature coefficient γ0 of 42.1 V-1 at zero bias, γmax of 105.35 V-1 at 0.2 V, and a reverse current of <10 nA/cm2. The NCD sheet resistance decreased from 4.1×1011 to 403.56 Ω/sq. as the carrier density Ns was increased from 3.5×105 to 1.5×1016 cm-2 by B2H6 doping. The 348 cm2/V-s mobility of the B-free NCD films was comparable to that of single crystal diamond. CL data revealed traps 0.6-0.8 eV from the NCD EV edge. [ABSTRACT FROM AUTHOR]