Optimizing ALD HfO2 for Advanced Gate Stacks with Interspersed UV and Thermal Treatments- DADA and MDMA Variations, Combinations, and Optimization

We have recently reported electrical performance improvements of atomic layer deposited (ALD) HfO2 films grown by use of a cyclical deposition and annealing scheme (termed DADA) compared to a single deposition with or without a post-deposition anneal (PDA). Likewise, a process for improving leakage and reliability characteristics of ALD HfZrO by use of an interspersed room temperature ultraviolet ozone (RTUVO) treatments, referred to as multi-deposition multi-room temperature annealing (MDMA), has recently been reported. We have developed a version of this MDMA process on our 300 mm clustered tool with in situ RTUVO treatments interspersed between ALD HfO2 depositions. In this report we compare these two processes (DADA vs. MDMA) for HfO2 dielectric formation in a low temperature MOSCAP flow with in-line measurements of the HfO2 and interface layer thicknesses.