Oxygen-soluble gate electrodes for prolonged high-κ gate-stack reliability

We propose the use of high-oxygen-solubility metalgate electrodes as a material of choice for high- κ gate stacks in order to prolong the time-dependent-dielectric-breakdown (BD) reliability. Our findings on n-channel metaloxidesemiconductor devices with these gate electrodes reveal that the application of low negative bias stress after a soft-BD (SBD) event helps to restore the oxygen ions and passivate the oxygen vacancy traps that comprise the percolation path. This can be a simple yet effective designfor-reliability tool to initiate the self-repair of the percolation path and operate the circuit for a prolonged period after repair. The only requirement for achieving this SBD reversibility is to choose gate electrodes that can serve as good oxygen reservoirs.