Impact of Hf content on positive bias temperature instability reliability of HfSiON gate dielectrics

Metal-oxide-semiconductor field-effect transistors (MOSFETs) incorporating HfSiON dielectrics with different compositions have been fabricated using atomic layer deposition (ALD) and their positive bias temperature instability (PBTI) reliability has also been investigated. The experimental results indicate that the oxide trapped charge (N_ot) dominates the PBTI degradation process, and after PBTI stress the increment of oxide trapped charges (ΔN_ot) is about 2-3 orders of magnitude greater than the generation of interface traps (ΔN_it). Moreover, higher Hf concentration results in more pre-existing traps but slower trap creation rate. The charge pumping technique has been utilized to characterize the interfacial parameters, ΔN_it, ΔN_ot, and ΔD_it (the generation of the density of interface trap per energy and area).