Pathways for advanced transistors using hafnium-based oxides by atomic layer deposition

Integration pathways were studied using transistors (to 0.25 μm feature size) with HfO 2 and HfH 2 /Al 2 O 3 sandwiches fabricated by ALD. The study included variation and characterization of the surface preparation and the post deposition anneals. Both active NH 3 and O 3 were used in the surface preparation and O 2 bearing and N bearing ambients were used in the PDA. Tight leakage distribution is evidenced in the HfO 2 transistors and confirms the ALD process control. Excellent I dsat and g m were measured (at 1 V overdrive) on the PMOS devices. The NMOS devices showed moderate performance. Further, both PMOS and NMOS characteristics, such as Jg, Vt, I dsat , and g m were found to scale with gate length in a manner similar to SiO 2 controls.