Yoshiki Kamata

High-k/Ge MOSFETs for future nanoelectronics

Recently developed high-permittivity (k) materials have reopened the door to Ge as a channel material in metal-oxide-semiconductor field-effect transistors (MOSFETs). High-k/Ge gate stacks are very promising for future nanoscale devices. This article reviews the opportunities and challenges of high-k/Ge MOSFET technology. The most important technical issue is the passivation of the Ge surface. Physical phenomena and electrical characteristics that depend on the high-k/Ge interface are discussed on the basis of the material properties of Ge oxide to provide insights for future progress.

Effects of nitrogen in HfSiON gate dielectric on the electrical and thermal characteristics

The effects of the nitrogen in the HfSiON gate dielectric on the electrical and thermal properties of the dielectric were investigated. It is clearly demonstrated that nitrogen enhances the dielectric constant of silicates. High dielectric constants of the HfSiON are maintained and boron penetration is substantially suppressed in the HfSiON during high temperature annealing. These properties are ascribed to the homogeneity of the bond structure in the film containing nitrogen through high temperature annealing.

Diffusion and activation of n-type dopants in germanium

The diffusion and activation of n-type impurities (P and As) implanted into p-type Ge(100) substrates were examined under various dose and annealing conditions. The secondary ion mass spectrometry profiles of chemical concentrations indicated the existence of a sufficiently high number of impurities with increasing implanted doses. However, spreading resistance probe profiles of electrical concentrations showed electrical concentration saturation in spite of increasing doses and indicated poor activation of As relative to P in Ge. The relationships between the chemical and electrical concentrations of P in Ge and Si were calculated, taking into account the effect of incomplete ionization. The results indicated that the activation of P was almost the same in Ge and Si. The activation ratios obtained experimentally were similar to the calculated values, implying insufficient degeneration of Ge. The profiles of P in Ge substrates with and without damage generated by Ge ion implantation were compared, and it ...

Dielectric properties of noncrystalline HfSiON

The dielectric properties of noncrystalline hafnium silicon oxynitride (HfSiON) films with a variety of atomic compositions were investigated. The films were deposited by reactive sputtering of Hf and Si in an O, N, and Ar mixture ambient. The bonding states, band-gap energies, atomic compositions, and crystallinities were confirmed by X-ray photoelectron spectroscopy (XPS), reflection electron energy loss spectroscopy (REELS), Rutherford backscattering spectrometry (RBS), and X-ray diffractometry (XRD), respectively. The optical (high-frequency) dielectric constants were optically determined by the square of the reflective indexes measured by ellipsometry. The static dielectric constants were electrically estimated by the capacitance of Au/HfSiON/Si(100) structures. It was observed that low N incorporation in the films led to the formation of only Si-N bonds without Hf-N bonds. An abrupt decrease in band-gap energies was observed at atomic compositions corresponding to the boundary where Hf-N bonds start to form. By combining the data for the atomic concentrations and bonding states, we found that HfSiON can be regarded as a pseudo-quaternary alloy consisting of four insulating components: SiO

High-performance poly-Ge short-channel metal–oxide–semiconductor field-effect transistors formed on SiO2 layer by flash lamp annealing

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Fabrication of HfSiON gate dielectrics by plasma oxidation and nitridation, optimized for 65 nm mode low power CMOS applications

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Effect of Hf-N bond on properties of thermally stable amorphous HfSiON and applicability of this material to sub-50nm technology node LSIs

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High-k/Ge p- & n-MISFETs with strontium germanide interlayer for EOT scalable CMIS application

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Process technologies for high density, high speed 16 megabit dynamic RAM

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Improvement in C-V characteristics of Ge metal-oxide semiconductor capacitor by H2O2 incorporated HCl pretreatment

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