Frequency dependent capacitance and conductance–voltage characteristics of Al/Si3N4/p-Si(1 0 0) MIS diodes

The frequency dependent capacitance–voltage (C–V-f) and conductance–voltage (G/w–V-f) characteristics of the metal–insulator–semiconductor (Al/Si3N4/p-Si) Schottky barrier diodes (SBDs) were investigated in the frequency range of 30 kHz–2 MHz. For each frequency, the C–V plots show a peak and the change in frequency has effects on both the intensity and position of the peaks. The C−2–V plot gives a straight line in wide voltage region, indicating that interface states and inversion layer charge cannot follow the ac signal in the depletion region, especially in the strong inversion and accumulation region. For each frequency, the plot of series resistance gives a peak, decreasing with increasing frequencies. Also, it has been shown that the interface states density exponentially decreases with increasing frequency. The C–V-f and G/w–V-f characteristics confirm that the Nss and Rs of the diode are important parameters that strongly influence the electric parameters in MIS structure.