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ABSTRACT: Bi-layer gate stacks consisting of a HfO<sub>2</sub> and an interfacial layer are fabricated by remote plasma oxidation (RPO) of Hf metal deposited on an Si substrate. Hf metal is fully oxidized by the RPO even at a temperature as low as 400°C due to radical oxygens, leading to an improvement in the quality of HfO<sub>2</sub> with less impact to the interfacial layer growth. An insufficient oxidation leads to a deterioration of mobility with increasing interface traps and positive bias temperature instability, which is likely caused by the oxygen vacancies acting as traps induced by the remaining Hf metal. The SiO<sub>2</sub>-like interface improves the mobility with reduced interface states. Full oxidation and the controlled SiO<sub>2</sub>-like interface demonstrate RPO as a promising way for gate-stack optimization.
IEEE Transactions on Electron Devices 06/2006; · 2.32 Impact Factor
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S. Kubicek,
A. Veloso,
K.G. Anil,
S. De Gendt,
M. Heyns,
M. Jurczak,
S. Biesemans,
A. Lauwers,
S. Hayashi, K. Yamamoto,
R. Mitsuhashi,
J.A. Kittl,
M. Van Dal,
S. Horii,
Y. Harada,
M. Kubota,
M. Niwa
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ABSTRACT: We show for the first time that full Ni silicidation (Ni-FUSI) of poly gates in combination with Hf based gate dielectrics meets the required device performance for the 65nm LSTP technology node. Important device parameters, like C<sub>inv</sub>, mobility and drive currents exhibit significant improvement without compromising the oxide integrity and reliability. The drive of nMOS and pMOS transistors for the V<sub>DD</sub>=1.1V at 10pA/μm off state leakage is 575μA/ μm and 1650 μA/μm respectively.
VLSI Technology, 2005. (VLSI-TSA-Tech). 2005 IEEE VLSI-TSA International Symposium on; 05/2005
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ABSTRACT: The HfO2/Si(001) interfaces formed by reactive dc sputter deposition of Hf buffer layer followed by HfO2 stacking were analyzed by high-resolution transmission electron microscopy, medium energy ion scattering (MEIS), and photoelectron spectroscopy using synchrotron-radiation lights. The present MEIS analysis determined the elemental depth profiles and revealed that no Hf buffer layer resulted in growth of SiO2 at the interface, and that the presence of the Hf layer led to the formation of Si-rich silicate-like interlayers. The binding energy shifts of Si-2p3/2 identified the chemical bonds of the interfacial layers and confirmed the formation of SiO2 (no buffer layer) and silicate layers (presence of the buffer layers) at the interfaces. The Hf-buffer layer suppresses the O diffusion toward the interface and thus the thicker the buffer layer, the thinner the Hf-silicate interlayer. The deposition condition of HfO2 (1.3 nm)/Hf (1.3 nm) has achieved the highest permittivity of 28 for HfO2 (3.6 nm) and 8 for the silicate layer (1.7 nm). © 2002 American Institute of Physics.
Applied Physics Letters 09/2002; 81(14):2650-2652. · 3.84 Impact Factor
