The preparation of Au/n-4H-SiC (MS) schottky diodes and the investigation their electrical characteristicsas function of frequency

In this study, Au/n-type 4H-SiC Schottky diodes were fabricated and their main electrical characteristics have been investigated as function of frequency by using the capacitance/conductance-voltage (C-V and G/w-V) measurements at room temperature. The doping density of donor atoms (ND), Fermi energy level (EF), and barrier height (?b(C-V)) values were obtained from the reverse bias C-2-V plots in the wide frequency range of 0,7 kHz-1MHz. Both C and G/w values were found as strongly function of frequency and decrease with increasing frequency as almost exponential. The changes in C and G/w values in depletion region were attributed to the particular density distribution of surface states (Nss) between metal and semiconductor. The series resistance (Rs)-logf plots were also obtained by using the C and G/w data and decreases with increasing frequency. The voltage dependent of Nss was also obtained from high-low frequency capacitance (CHF-CLF) method and shows a peak. Especially the concave curvature in high frequency C-V plots for forward biases was attributed to the value of Rs.