Characterization of Al2O3–HfO2–Al2O3 sandwiched MIM capacitor under DC and AC stresses

In this paper, electrical properties and reliability of high capacitance density Metal–Insulator–Metal (MIM) capacitor with sandwiched hafnium-based dielectric is analyzed using three kinds of voltage stress; constant voltage stress (CVS), unipolar voltage and bipolar voltage stresses. The fabricated MIM capacitor shows not only high capacitance density but also low leakage current density of about ∼10 nA/cm2 at room temperature and 1 V. The relative variation of capacitance (ΔC/C0) increases and the variation of voltage linearity (α/α0) gradually decreases with stress-time due to the charge trapping effect in the high-k dielectric. The relative variations of capacitance and voltage linearity show the greater change by the bipolar voltage stress than CVS and unipolar voltage stresses.

► We analyze the electrical properties and reliability of Al2O3–HfO2–Al2O3 sandwiched MIM capacitor. ► We analyzed using three kinds of voltage stress; constant, unipolar and bipolar voltage stresses. ► The fabricated MIM capacitor shows high capacitance density and low leakage current. ► The capacitance increases and VCC decreases with stress-time due to charge trapping.