Interface characterization and carrier transportation in metal/HfO2/silicon structure

Abstract

Metal-oxide-semiconductor capacitors incorporating HfO2 dielectrics were fabricated and investigated. In this work, the structural and electrical characterizations were performed at the interfaces of HfO2∕Si and Al∕HfO2, respectively. The physical analyses reveal that an interfacial layer of Hf-silicate between 700°C-annealed HfO2 and Si was formed. The dominant conduction mechanisms of the Al∕HfO2∕p-Si structure are the Schottky emission at high temperatures (≳465K) and low electric fields (≲2.2MV∕cm) and the Fowler-Nordheim tunneling at low temperature (77K) and high electric fields (≳2.6MV∕cm), respectively. The electron effective mass in HfO2 and the barrier height at the Al∕HfO2 interface are evaluated using both the intercept of the Schottky plot and the slope of the Fowler-Nordheim plot. Therefore, the barrier height at the Al∕HfO2 interface was determined to be about 0.94eV. The electron effective masses in HfO2 are 0.4m0 and 0.09m0 for the effective oxide thickness (EOT)=6nm and EOT=3.15nm, respectively.

Structural and resistance switching properties of ZnO/SrTiO3/GaAs heterostructure grown by laser molecular beam epitaxy

“…By contrast, in our case, the disappearance of the hysteresis can be considered as disappearance of the Schottky barrier at a low temperature. This is somewhat similar to the temperaturedependent I-V curve in other systems of metal-oxidesemiconductor structures, such as Al/ HfO 2 / SiO 2 / p-Si, 24 TaN/ ZrO 2 / SiO 2 / p-Si, 25 etc. These temperature-dependent I-V behaviors always show similar performances by inducing an interfacial layer.…”

Accurate modeling of Metal/HfO2/Si capacitors

“…de Electrónica, Facultad de Ciencias, University of Granada, Av. Fuentenueva, S/N., 18071 Granada, Spain e-mail: agodoy@ugr.es F.G. Ruiz e-mail: franruiz@ugr.es best candidates to replace SiO 2 [2], and preliminary results confirm the expectations concerning the possibilities of this material to serve as gate insulator of future devices [3].…”

Theoretical Study on Leakage Current in MOS with High-K Dielectric Stack: Effects of In-plane-Longitudinal Kinetic Energy Coupling and Anisotropic Masses

“…4. Here, the electron effective masses of HfO 2 (m HfO2 ) of 0.17 m 0 and 0.4 m 0 were used [1,16]. It is shown that the leakage current for m HfO2 of 0.4 m 0 is about eight orders of magnitude lower than that for m HfO2 of 0.17 m 0 .…”

“…Several high-K gate dielectrics have been investigated to replace SiO 2 . Among them, HfO 2 and hafnium-based silicates are promising due to their good thermal stabilities and favorable energy band alignments to Si (100) [1,2]. An ultrathin interfacial oxide layer, which often forms during the fabrication process, has been used for a high quality Si-SiO 2 interface underlying the high-K gate dielectrics.…”