Effect of Hf Sources, Oxidizing Agents, and NH₃/Ar Plasma on the Properties of HfAlO_x Films Prepared by Atomic Layer Deposition

Abstract

We construct a D2-D8-D8 configuration in string theory, it can be described at low energy by two dimensional field theory. In the weak coupling region, the low energy theory is a nonlocal generalization of Gross-Neveu(GN) model which dynamically breaks the chiral flavor symmetry U(N f ) L × U(N f ) R at large N c and finite N f . However, in the strong coupling region, we can use the SUGRA/Born-Infeld approximation to describe the low energy dynamics of the system. Also, we analyze the low energy dynamics about the configuration of wrapping the one direction of D2 brane on a circle with anti-periodic boundary condition of fermions. The fermions and scalars on D2 branes get mass and decouple from the low energy theory. The IR dynamics is described by the QCD 2 at weak coupling. In the opposite region, the dynamics has a holographic dual description. And we have discussed the phase transition of chiral symmetry breaking at finite temperature. Finally, after performing T-duality, this configuration is related to some other brane configurations.

Annealing properties of open volumes in HfSiOx and HfAlOx gate dielectrics studied using monoenergetic positron beams

“…The major impurities of HfSiO x have been found to be carbon ͑10 20 cm −3 ͒ and hydrogen ͑10 20 -10 21 cm −3 ͒, 21 and those of HfAlO x are chlorine ͑10 20 cm −3 ͒, carbon ͑10 19 cm −3 ͒, and hydrogen ͑10 19 cm −3 ͒. 8 We used a monoenergetic positron beam to measure the Doppler broadening spectra of annihilation radiation for the samples as a function of incident positron energy E. For each E, a spectrum with 1 ϫ 10 6 total counts was obtained. The low-momentum part of the spectrum was characterized using the S parameter, which is defined as the number of annihilation events over the energy range of 511± 0.76 keV.…”

“…Details of the deposition methods and the electric properties of MOS using such materials are described elsewhere. 8,20,21 The 4.5-nm-thick Hf 0.6 Si 0.4 O x films were formed by metalorganic chemical-vapor deposition ͑MOCVD͒ using hafnium tetra-t-butoxide ͑HTB͒ and Si 2 H 6 without using an oxidizing gas. Before the deposition, 0.9-nm-thick SiON films were grown by wet oxidation using N 2 O/H 2 .…”

“…Since their silicon or aluminum binary oxides ͑such as HfSiO x and HfAlO x ͒ retain an amorphous structure after hightemperature heat treatment, these binary oxides are now the most promising candidates to become the gate dielectric for next generation MOSFETs. 1, [3][4][5][6][7][8] Although the permittivity and the diffusion properties of impurities, such as boron penetration from a polycrystalline Si gate, are thought to be related to the microscopic structures of high-k materials, 6,[9][10][11] information about the atomic configuration is rather limited. Positron annihilation is an established technique for investigating defects and open spaces ͑or open volume͒ in solids.…”

Hafnium-Based Gate Dielectric Materials

“…Normally, trimethyl-aluminum (TMA: Al(CH) 3 [111] or intermittent NH 3 /Ar plasma treatment [112] is effective for reducing the carbon content in the material and this leads to the decrease in the leakage current through the film [112].…”

Electrical properties of 0.5 nm thick Hf-silicate top-layer∕HfO2 gate dielectrics by atomic layer deposition

“…[12][13][14][15] Recently, there have been reports of using Hf amide type precursors such as Hf͓N͑CH 3 ͒͑C 2 H 5 ͔͒ 4 for HfO 2 or Hf-aluminate film formation to solve problems such as excessive particles or residual chlorine when using HfCl 4 precursors. 15,16,19 Furthermore, ALD HfO 2 films have been deposited at low temperatures ͑around 300°C͒, using a Hf͓N͑CH 3 ͒͑C 2 H 5 ͔͒ 4 precursor and O 3 as the oxidant during ALD, instead of H 2 O. Such films contained much lower residual impurities, such as carbon or nitrogen, than with previous precursors.…”