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

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 (77–350 K). The I(V) characteristics show a double-barrier phenomenon, which gives a low and high barrier height ( $$\phi _{{bn}}^{{\text{L}}}$$ = 0.91 eV, $$\phi _{{bn}}^{{\text{H}}}$$ = 1.55 eV), with a difference of Δϕbn = 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 ϕbn decreases with decreasing of temperature and gives a temperature coefficient α = 1.0 × 10–3 eV/K and ϕbn (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 σ = 1.8 × 10–20 cm2, and defect concentration NT = 6.2 × 1013 cm–3 were calculated from Arrhenius plots.