Electrical Properties of As-Deposited ALD HfO2 Films Related to Silicon Surface State

In this paper, we present an experimental study of the electrical properties of the as-deposited HfO2films obtained by atomic layer deposition (ALD) method from tetrakis dimethylamino hafnium and water vapors at 200°C as a function of the silicon substrate preparation, in terms of Si-H and Si-OH terminated surfaces. High frequency C- V characteristics have proven that relatively higher effective dielectric constant, lower fixed charge at the Si-HfO2 interface and lower oxide trapped charge were obtained on MOS capacitors with HfO2 dielectric performed on Si-OH terminated Si surface with respect Si-H terminated surface, proving a more robust Si-O-Hf interface with respect to Si-Hf-O interface.