Swift heavy ion induced capacitance and dielectric properties of Ni/n-GaAs Schottky diode

Abstract

The in-situ capacitance and dielectric properties of 25 MeV C4+ ion irradiated Ni/n-GaAs Schottky barrier diode (SBD) were studied at 100 kHz in the fluence range 5 × 1010 – 5 × 1013 ions/cm2. The investigation shows reduction in capacitance and charge density with increase in ion fluence. Consequent changes were observed in other related parameters like conductance, dielectric constant, dielectric loss, loss tangent and electrical modulus. The results were interpreted in terms of generation of swift heavy ion induced acceptor trap states by electronic energy loss mechanism. Besides, the switch over characteristics of depletion to inversion regions in the CV plot reveals minority carrier recombination centers also. The dispersion and relaxation peaks observed in bias dependent dielectric plots were ascribed to the polarization and relaxation mechanism due to the interfacial trap states. The traps and recombination centers were found to alter the barrier characteristics of the fabricated SBD depending upon the ion fluence.