Atomic Defects Profiling and Reliability of Amorphous Al2O3 Metal-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- V), capacitance-voltage ( CV), conductance-voltage (GV) (i.e., defect spectroscopy), and low-field I- V hysteresis analysis. The defect energies extracted ( ETH = 1.55 and 3.55 eV) are consistent with oxygen vacancies and aluminum interstitials. The voltage-dependent dielectric breakdown (VDDB) statistics of a-Al2O(3) is investigated using ramped voltage stress (RVS). The VDDB statistics show a complex and polaritydependent breakdown statistics, correlating with defect distributions, which allows estimating the a-Al2O3 bondbreaking parameters with the support of multiscale atomistic simulations of the breakdown process.

Automated summary

We present a comprehensive characterization of amorphous alumina in MIM stacks, extracting the distribution of atomic defects and bond-breaking process parameters. The active defects were profiled through various simulations, and the extracted defect energies were consistent with oxygen vacancies and aluminum interstitials. The breakdown statistics of voltage-dependent dielectric breakdown were investigated, showing complex and polarity-dependent breakdown patterns correlating with defect distributions.