On the profile of frequency dependent interface states and series resistance in Au/p-InP SBDs prepared with photolithography technique

The frequency dependent of the forward and reverse bias capacitance-voltage (C-V) and conductance-voltage (G/w-V) characteristics of Au/p-InP SBDs have been investigated in the frequency range of 20 kHz-10 MHz and voltage range of -5 - 5 V at room temperature. The effects of surface states (N (ss)) and series resistance (R (s)) on C-V and G/w-V characteristics have been investigated in detail. The frequency dependent N (ss) and R (s) profiles were obtained for various applied bias voltages. The experimental results show that the main electrical parameters of Au/p-InP SBD such as barrier height (I broken vertical bar(B)), the density of acceptor concentration (N (A)), N (ss) and R (s) were found strongly frequency and voltage dependent. The values of C and G/w decrease with increasing frequency due to a continuous distribution of N (ss) localized at the metal/semiconductor (M/S) interface. The effect of R (s) on C and G is found considerably high especially at high frequencies. Therefore, the high frequencies of the values of C and G were corrected for the effect of R (s) in the whole measured bias range to obtain the real diode capacitance C (c) and conductance G (c) using the Nicollian and Goetzberger technique. The distribution profile of R (s)-V gives a peak depending on the frequency especially at low frequencies and disappears with increasing frequencies due to the existence of N (ss) at the M/S interface.