François Bertin

Bio: François Bertin is an academic researcher from University of Grenoble. The author has contributed to research in topics: Silicon & Porosimetry. The author has an hindex of 16, co-authored 59 publications receiving 764 citations. Previous affiliations of François Bertin include Commissariat à l'énergie atomique et aux énergies alternatives & European Automobile Manufacturers Association.

Medium resolution off-axis electron holography with millivolt sensitivity

Abstract: Focused ion beam prepared silicon calibration specimens with boron doped layers have been examined using off-axis electron holography. By using a state-of-the-art FEI Titan microscope with unprecedented stability, we have been able to record holograms for time periods of 128s with contrast levels of almost 40% and an average signal on the charge coupled device camera of 30 000 counts. A consequence of this is a significant improvement of the signal-to-noise ratio in the phase images allowing steps in potential of less than 0.030±0.003V to be measured if sufficient care is taken during specimen preparation.

Attenuated total reflection spectroscopy for infrared analysis of thin layers on a semiconductor substrate

Abstract: A theoretical analysis based on a perturbation method is used to elucidate the results of attenuated total reflection (ATR) measurements performed on silicon oxide layers of different thicknesses on silicon substrates. This analysis shows that the absorbance ATR spectrum in p polarization is the image of the layer energy loss function, under specific conditions. It is pointed out that the enhanced sensitivity of ATR is controlled by the air gap thickness, the optical properties of the media involved, and the probing light polarization. An exact ATR spectrum simulation using a matrix formalism showed that straightforward interpretation in terms of the layer dielectric function is limited to a very narrow layer thickness range. The ATR spectrum fitting process is considered for layers out of this range and evaluated for the interpretation of experimental silicon oxide layer spectra.

Imaging of stored charges in Si quantum dots by tapping and electrostatic force microscopy

Abstract: We studied the charge storage and subsequent imaging of silicon quantum dots (SiQD) embedded in a SiO2 film by using atomic-force microscopy (AFM) in tapping and electrostatic force microscopy (EFM) modes. The controllable deposition of both positive and negative localized charges in SiQD is described. The dynamics of the deposited charges is studied and the charge decay time constant is determined from the measurements. A simple analysis is presented to explain the contrast in tapping and EFM images and to quantify the total amount of stored charge.

Method to assess the grain crystallographic orientation with a submicronic spatial resolution using Kelvin probe force microscope

Abstract: In thin polycrystalline copper film, a direct correlation between the grain crystallographic orientation and the work function has been evidenced by comparing Kelvin probe force microscope (KFM) mapping and electron backscattered diffraction analysis performed over the same region. As a result, work function mapping provided by KFM technique can be used to assess the crystallographic properties of thin layers with a spatial resolution better than 100nm.

Surface Organometallic and Coordination Chemistry toward Single-Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities

Abstract: Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities Christophe Copeŕet,*,† Aleix Comas-Vives,† Matthew P. Conley,† Deven P. Estes,† Alexey Fedorov,† Victor Mougel,† Haruki Nagae,†,‡ Francisco Nuñ́ez-Zarur,† and Pavel A. Zhizhko†,§ †Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1−5, CH-8093 Zürich, Switzerland ‡Department of Chemistry, Graduate School of Engineering Science, Osaka University, CREST, Toyonaka, Osaka 560-8531, Japan A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str. 28, 119991 Moscow, Russia

Four-Dimensional Scanning Transmission Electron Microscopy (4D-STEM): From Scanning Nanodiffraction to Ptychography and Beyond.

Abstract: Scanning transmission electron microscopy (STEM) is widely used for imaging, diffraction, and spectroscopy of materials down to atomic resolution. Recent advances in detector technology and computational methods have enabled many experiments that record a full image of the STEM probe for many probe positions, either in diffraction space or real space. In this paper, we review the use of these four-dimensional STEM experiments for virtual diffraction imaging, phase, orientation and strain mapping, measurements of medium-range order, thickness and tilt of samples, and phase contrast imaging methods, including differential phase contrast, ptychography, and others.

Formation, structure, and reactivity of amino-terminated organic films on silicon substrates.

Abstract: Amino-functionalized organic films were prepared by self-assembling 3-aminopropyltriethoxysilane (APTES) on silicon wafers in either anhydrous toluene or phosphate-buffered saline (PBS) for varied deposition times. Fourier transform infrared spectroscopy (FTIR) and ellipsometry have shown that the structure and thickness of APTES films are governed by the deposition time and reaction solution. Deposition from an anhydrous toluene solution produces APTES films ranging from 10 to 144 A in thickness, depending on the reaction time. FTIR spectra indicate that film growth initially proceeds by adsorption of APTES to the silicon surface followed by siloxane condensation, and after an extended period of time APTES molecules accumulate on the underlying APTES film by either covalent or noncovalent interactions. In contrast, spectroscopically indistinguishable APTES films in thickness ranging from 8 to 13 A were formed when deposition was conducted in aqueous solutions. Measured water contact angles indicate that APTES films deposited in aqueous solutions are more hydrophilic compared to those prepared in toluene solutions. Fluorescence measurements revealed that APTES films prepared in toluene solutions contain more reactive surface amino groups by ca. 3 to 10 times than those prepared in aqueous solutions for the identical reaction time.

Plasma processing of low-k dielectrics

Abstract: This paper presents an in-depth overview of the present status and novel developments in the field of plasma processing of low dielectric constant (low-k) materials developed for advanced interconnects in ULSI technology. The paper summarizes the major achievements accomplished during the last 10 years. It includes analysis of advanced experimental techniques that have been used, which are most appropriate for low-k patterning and resist strip, selection of chemistries, patterning strategies, masking materials, analytical techniques, and challenges appearing during the integration. Detailed discussions are devoted to the etch mechanisms of low-k materials and their degradation during the plasma processing. The problem of k-value degradation (plasma damage) is a key issue for the integration, and it is becoming more difficult and challenging as the dielectric constant of low-k materials scales down. Results obtained with new experimental methods, like the small gap technique and multi-beams systems with separated sources of ions, vacuum ultraviolet light, and radicals, are discussed in detail. The methods allowing reduction of plasma damage and restoration of dielectric properties of damaged low-k materials are also discussed.