Experimental Investigation of Border Trap Generation in InGaAs nMOSFETs With Al2O3 Gate Dielectric Under PBTI Stress

The reliability performance of InxGa1-xAs n-type metal-oxide-semiconductor field-effect transistors with Al2O3 gate dielectric under positive-bias temperature instability stress is investigated systematically. A model of stress-induced border traps was proposed to interpret all charge pumping and I-V experimental results excellently. The stress-induced border traps include recoverable donor traps and permanent acceptor traps with respective energy densities Delta D-SOX(Donor) (E) and Delta D-SOX(Acceptor) (E). The shapes of Delta D-SOX(Donor) (E) and Delta D-SOX(Acceptor) (E) have been extracted from experimental data Delta D-SOX(Acceptor) (E) mainly distributes in the conduction band of InGaAs with a tail extending to the mid-gap, whereas Delta D-SOX(Donor) (E) has a large distribution inside the energy gap and extends to the conduction band. The high density of Delta D-SOX(Donor) (E) in the energy gap induces large degradation in the OFF-current, which is particularly serious when the In composition x is raised to 0.65.