Current--Voltage, Capacitance--Voltage--Temperature, and DLTS Studies of Ni|6H-SiC Schottky Diode

Abstract

In this paper, we give a systematical description of Ni|6H-SiC Schottky diode by current--voltage I(V) characteristics at room temperature and capacitance--voltage C(V) characteristics at various frequencies (10-800 kHz) and various temperatures (77-350oK). The I(V) characteristics show a double-barrier phenomenon, which gives a low and high barrier height (phiLbn=0.91 eV, phiHbn=1.55 eV), with a difference of Deltaphibn=0.64 eV. Also, low ideality factor nL=1.94 and high ideality factor nH=1.22 are obtained. The C-V-T measurements show that the barrier height phibn decreases with decreasing of temperature and gives a temperature coefficient alpha=1.0·10-3 eV/K and phibn(T=0 K)=1.32 eV. Deep-level transient spectroscopy (DLTS) has been used to investigate deep levels in the Ni|6H-SiC Schottky diode. The traps signatures such as activation energies Ea=0.50±0.07 eV, capture cross-section sigma=1.8·10-20 cm2, and defect concentration NT=6.2·1013 cm-3 were calculated from Arrhenius plots. Keywords: si1licon carbide, Schottky diodes, I-V, C-V-T, deep-level transient spectroscopy (DLTS).