Origin of forward bias capacitance peak and intersection behavior of C and G/w of Ag/p-InP Schottky barrier diodes

Abstract

Frequency-dependent electrical characteristics of Ag/p-InP diodes have been determined using impedance spectroscopy at room temperature. Series resistance (Rs) and interface state(s) (Nss) values were extracted from capacitance (C) and conductance (G/w) data using the Nicollian and Goetzberger and Hill–Coleman methods, respectively. C and G/w data were also corrected in the whole measured bias voltage range to obtain real diode capacitance Cc and conductance Gc values in order to see the effects of Rs. Both the C–V and Rs–V plots showed anomalous peak in depletion region especially at low frequencies due to the existence of Nss. C–V and G/w–V plots crossed at a certain bias voltage and this point shifted toward negative bias voltages with increasing frequency and then disappeared at 3MHz. Also, decrease in C values corresponds to an increase in G/w values in the same bias voltages.