Reliability characteristics of metal-oxide-semiconductor capacitors with 0.72 nm equivalent-oxide-thickness LaO/HfO2 stacked gate dielectrics

La-incorporated HfO2 could improve the thermal stability and interface trap quality. Laminated structures with different doping positions and thicknesses were fabricated by RF magnetron co-sputtering method. The physical and electrical properties of HfO2/HfLaO/p-Si and HfLaO/HfO2/p-Si structures after 850 °C postannealing were analyzed. And the time dependent dielectric breakdown (TDDB) characteristics were also analyzed for metal-oxide-semiconductor (MOS) capacitors with atomic-layer-deposited (ALD) HfLaO gate dielectrics. For TDDB characteristics, the Weibull slopes were independent of stress voltages and capacitor areas, but they were dependent on the stress temperatures. The electric-field acceleration parameter (γ) is about 4.3–4.5 MV/cm. The maximum voltage (Vg) for 10-year TDDB lifetime under 85 °C operation is Vg = 2.03 V, or equivalently 6.1 MV/cm.

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► La-incorporated HfO2 could improve the thermal stability and interface trap quality.
► TDDB characteristics of advanced MOS devices incorporating ALD HfLaO gate dielectrics were studied.
► The satisfactory TDDB characteristics suggest that ALD HfLaO gate dielectric is suitable for future CMOS applications.