Passivation by N implantation of the SiO2/SiC acceptor interface states: Impact on the oxide hole traps and the gate oxide reliability

This study compares p-MOS capacitors fabricated on N implanted and on virgin 4H-SiC. The former sample have N at the SiO/SiC interface, the latter have not. To investigate the presence of deep and shallow hole traps at the SiO/SiC interface, high frequency and quasistatic capacitance voltage measurements under dark have been compared for bias sweeping from accumulation to depletion and from depletion to accumulation, the latter after white light illumination. The presence of N has an effect on the density of the shallow donor like traps but no effect on the deep ones. The positive charge trapped in the oxide and/or at the oxide interface after equivalent tunneling hole injection have been compared and are equivalent. Time dependent dielectric breakdown tests have been compared too. The oxide grown on N implanted SiC broken at lower electric field. © 2010 Materials Research Society.