Atomic Defects Profiling and Reliability of Amorphous Al2O3Metal-Insulator-Metal Stacks

We present a comprehensive characterization of amorphous alumina (a-Al2O3) high- {k} dielectric in metal-insulator-metal (MIM) stacks, self-consistently extracting the space-energy distribution of a-Al2O3 atomic defects and the related bond-breaking process parameters. Active defects are profiled via simultaneous simulation of current-voltage ( {I} - \textit {V} ), capacitance-voltage (CV), conductance-voltage (GV) (i.e., defect spectroscopy), and low-field {I} - {V} hysteresis analysis. The defect energies extracted ( {E}_{TH}= 1.55 and 3.55 eV) are consistent with oxygen vacancies and aluminum interstitials. The voltage-dependent dielectric breakdown (VDDB) statistics of a-Al2O3 is investigated using ramped voltage stress (RVS). The VDDB statistics show a complex and polarity-dependent breakdown statistics, correlating with defect distributions, which allows estimating the a-Al2O3 bond-breaking parameters with the support of multiscale atomistic simulations of the breakdown process.