The electrical properties of polycrystalline aluminum nitride (A1N) films grown by reactive dc magnetron sputtering are investigated in the transient and the steady-state regimes through metal-insulator-metal (MIM) structures with molybdenum (Mo) as metal electrodes. Measurements of current-time, current-voltage, and current-temperature characteristics are performed on A1N MIM structures. The extracted dielectric constant is 9.9. The transient current is observed to follow the empirical Curie-Von Schweidler law and its dependence on the applied field and the operating temperature is modeled. The time approach result is compared with the frequency-approach result by measuring the permittivity dispersion for low frequencies. Also, all the leakage mechanisms in A1N are identified in the steady-state regime depending on the applied field range. For a low electric field, the conduction mechanism is the Ohmic regime and the A1N resistivity is estimated to be 2.1 × 10~(15) Ω cm at room temperature. For higher electric fields, the ionic conduction is observed to be the dominant mechanism while the Poole-Frenkel transport is identified in the breakdown (BD) vicinity. A statistical approach is used to study the BD strength of the A1N through the Weibull distribution. The critical field for the dielectric BD ranges from 4.64 to 5.84 MV cm~(-1).
展开▼
