On the profile of temperature dependent series resistance in Al/Si3N4/p-Si (MIS) Schottky diodes

The temperature dependence of capacitance–voltage (C–V) and conductance–voltage (G/w–V) characteristics of metal–insulator–semiconductor (Al/Si3N4/p-Si) Schottky barrier diodes (SBDs) was investigated by considering series resistance effect in the temperature range of 80–300 K. It is found that in the presence of series resistance, the forward bias C–V plots exhibit a peak, and experimentally show that the peak positions with a maximum at 260 K shift toward lower voltages with increasing temperature. The C–V and (G/w–V) characteristics confirm that the interface state density (Nss) and series resistance (Rs) of the diode are important parameters that strongly influence the electric parameters of MIS structures. The crossing of the G/w–V curves appears as an abnormality compared to the conventional behavior of ideal Schottky diode. It is thought that the presence of series resistance keeps this intersection hidden and unobservable in homogeneous Schottky diodes, but it appears in the case of inhomogeneous Schottky diode. In addition, the high frequency (Cm) and conductance (Gm/w) values measured under both reverse and forward bias were corrected for the effect of series resistance to obtain the real diode capacitance.