Investigation of HFO_2 dielectric stacks deposited by ALD with a mercury probe

摘要

In this paper, a mercury probe is used to characterize electrically HfO_2 dielectric stacks. Its effectiveness and limitations are first investigated through C-V measurements analysis. Particularly, an new analytic electrical model is proposed to explain the frequency-dependence of C-V characteristics not only due to classical series resistance effects. An application to the study of different HfO_2 films is finally presented. It reveals, on as-deposited high-k oxides, the presence of a moderated-κ interfacial layer, which composition can change after post-deposition anneals. The stretch out of C-V curves due to polysilicon deposition and doping activation annealing is also reported.