Reliability characteristics of metal-oxide-semiconductor capacitors with 0.72nm 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 850C 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 (?) is about 4.34.5MV/cm. The maximum voltage (Vg) for 10-year TDDB lifetime under 85C operation is Vg=2.03V, or equivalently 6.1MV/cm.
la-incorporated hfo2 high-k dielectric tddb reliability