Effects of the electrical stress on the conduction characteristics of metal gate/MgO/InP stacks
Abstract The degradation dynamics and post-breakdown current–voltage ( I – V ) characteristics of magnesium oxide (MgO) layers grown on n and p-type indium phosphide (InP) substrates subjected to electrical stress were investigated. We show that the current–time ( I – t ) characteristics during degradation can be described by a power-law model I ( t ) =  I 0 t − α , where I 0 and α are constants. It is reported that the leakage current associated with the soft breakdown (SBD) failure mode follows the typical voltage dependence I  =  aV b , where a and b are constants, for both injection polarities but in a wider voltage range compared with the SiO 2 /Si system. It is also shown that the hard breakdown (HBD) current is remarkably high, involving large ON–OFF fluctuations that resemble the phenomenon of resistive switching previously observed in a wide variety of metal oxides.