Single-shot Excimer Laser Annealing (ELA) was performed onto Si surface that was previously B+ implanted with or without Ge+ pre-amorphization. As a result, p+ type USJ (Ultra-Shallow Junction) has been formed. In process analysis, using Infrared Spectroscopic Ellipsometry (IR-SE) has been performed and compared with conventional 4-point probe method. Also, the corresponding crystallinity for the USJ of Si surface has been studied using Ultraviolet-Visible (UV-Vis) Spectroscopic Ellipsometry. In the case of pre-amorphization by Ge+ implantation, the laser energy density threshold required for melting the surface, and therefore for electrical activation, decreased drastically because of the difference in the thermodynamic properties of the amorphized Si. Estimation of the junction depth shows a shallower junction when using UV-SE, as compared to IR-SE. This can be explained by the fact that, in the UV range, the crystallinity of the top layer is predominant while IR-SE is more sensitive to dopant activation. This efficient single-shot ELA is a candidate for the USJ formation for sub-0.1 μm CMOS transistors. The effective method for investigating the activation state related to the crystallinity by using UV-SE and IR-SE is expected to apply as a non-contact analytical tool for USJ formation.

In this work, SiO2-like films have been deposited in a capacitive coupled parallel plate reactor using low pressure, pulsed O-2/VTMS plasmas. The influence of the duty cycle and of the period on the structure of films at fixed gas feed composition are shown. It has been demonstrated that the chemical process developed depends very much on the modulation parameters, and that the OFF time significantly contributes to the overall process kinetics. Furthermore, some indication have been obtained on the possibility of getting multistack gas barrier coatings by alternating organic and inorganic layers, in which the inorganic layer is deposited by means of modulated plasma processes based on vinyltrimethylsilane feeds.

The use of indium tin oxide (ITO) in conjunction with polymeric substrates requires deposition at low temperatures or room temperature, and with a limited or no thermal treatment. This process results in high resistivity materials. To achieve practical resistivity levels, we replaced ITO, the workhorse in organic optoelectronic devices, with an ITO/Ag/ITO tri-layer anode. This material yielded the desired electrical properties without a significant effect on its optical properties. For example, a sheet resistance of 15 Omega/square and an optical transmission of 90% at 550 nm were obtained for a tri-layer film in which thickness of each ITO layer is 50 nm and the Ag layer thickness is 8 nm. The use of these tri-layer anodes in CuPc-C-60-based organic solar cells led to an increase in the fill factor under illumination, and thus an improvement of the external power conversion efficiency. (C) 2009 Elsevier B.V. All rights reserved.

Spectroscopic Ellipsometric (SE) is a non contact, non destructive optical characterization technique which allows the precise determination of the refractive indices and thicknesses of thin films. Very sensitive to any optical contrast, S.E. is now also being applied to the characterization of organic materials such OLED or for a range of Solar Cells that require thin films; all parameters (complex refractive index and thickness) of each layer can be obtained from one single measurement. In this paper we will focus on the determination of the thickness and refractive index of ZnO. We will also demonstrate how a SE measurement in different spectral range can give access to different properties of the ZnO & TCO's layers such as electrical properties (resistivity, resistance) or doping differentiation. We will introduce the SE measurement of encapsulated sample through the back side of the substrate and the extration film's resistivity.

The optical properties of thin NiCrOx layers were investigated by spectroscopic ellipsometry (SE). The layers were coated on float glass by magnetron sputtering at different oxygen partical pressures (20% to 30% oxygen in the sputtering gas) and the influence of the degree of oxidation was considered in details. The optical constants of the films n and k, in the visible to near infrared spectral range (0.35 to 17 mu m), appear to be extremely sensitive to their chemical composition. Complementary studies were carried out using Fourier transform infrared ellipsometry (FTIR-SE) to determine the optical conductivity of the films and compare it with four-points-probe measurements.

We have investigated the influence of the poly(3,4-ethylenedioxythiophene)-blend-poly(styrene-sulfonate) (PEDOT:PSS) layer on the short-circuit current density (Jsc) of single planar heterojunction organic solar cells based on a copper phthalocyanine (CuPc)-buckminsterfullerene (C60) active layer. Complete optical and electrical modeling of the cell has been performed taking into account optical interferences and exciton diffusion. Comparison of experimental and simulated external quantum efficiency has allowed us to estimate the exciton diffusion length to be 37 nm for the CuPc and 19 nm for the C60. The dependence of short-circuit current densities versus the thickness of the PEDOT:PSS layer is analyzed and compared with experimental data. It is found that the variation in short-circuit current densities could be explained by optical interferences.

Ellipsometric porosimetry (EP) is a non contact, non destructive approach based on a spectroscopic ellipsometric measurement which allows the precise determination of the refractive indices and thicknesses of the porous films. EP combined spectroscopic ellipsometric technique with a suitably adapted adsorption chamber. EP accords the great advantage of performing an in situ fast spectroscopic ellipsometric measurement at each stabilized pressure interval. From this combination, we can obtain morphological information such as open and closed porosity, pore size distribution, etc for thin films with an excellent sensitivity. In this paper we will focus on a SiOCH porous low-K sample. Using EP we will demonstrate that it is a porous hydrophobic material.We will then study the effect of plasma treatment on the material. The damaged layer will be characterized. By using water as an absorptive, we will be able to demonstrate the water degradation effect on treated materials.

We have studied the structural properties of tensile-strained Si layers grown on polished Si0.6Ge0.4 and Si0.5Ge0.5 virtual substrates as a function of their thickness. Two gaseous precursor chemistries have been assessed for the reduced pressure-chemical vapour deposition of the sSi layers: SiH2Cl2 at 700 degrees C and SiH4 at 600 degrees C. We have used specular x-ray reflectivity and spectroscopic ellipsometry to gain access to the sSi layer thickness ( and the associated sSi growth rate). The surfaces of sSi layers grown at 600 degrees C using SiH4 are characterized by a small spatial wavelength ( a few hundred nm) roughness. Meanwhile, some lines along the < 1 1 0 > directions can be observed for thick sSi layers grown at 700 degrees C using SiH2Cl2, hinting at the presence of stacking faults. We obtained (for 10 mu m x 10 mu m atomic force microscopy images) surface root-mean-square roughness (Z ranges) between 0.19 and 0.36 nm (1.8 and 3.9 nm). By comparison, the rms roughnesses ( the Z range) associated with 360 mu m x 368 mu m optical interferometry images are between 0.7 and 1.4 nm (7.1 and 12.1 nm), with some small amplitude but very long spatial wavelength (tens of mu m) surface cross-hatch remaining on Si0.6Ge0.4 VS. The interfaces between sSi and SiGe are very abrupt, as illustrated by high-resolution transmission electron microscopy and by the Ge decay profile in secondary ions mass spectrometry: 0.73 nm/decade for sSi on Si0.5Ge0.5 VS and 1.06 nm/decade for sSi on Si0.6Ge0.4 VS, more or less independently of the sSi growth chemistry. The larger value for sSi on Si0.6Ge0.4 VS is most probably due to some instrumental broadening linked to the small remaining cross-hatch.

Spectroscopic ellipsometry is the technique of choice to characterize thickness and refractive indices of transparent and semi-transparent thin layers with thickness ranging from few Angstroms to few micrometers. However, in case of porous thin film, traditional EMA (Effective Medium Approximation) fails to provide qualitative information on porosity. However, Spectroscopic Ellipsometry can benefit elaborated hardware and software set-up involving the adsorption/desorption of an adsorbate in the porous thin film, we call it, Ellipsometry Porosimetry Atmospheric (EPA) and the adsorbate is water. The change in refractive index induced by the introduction of water is measured and thanks to Lorentz Lorenz effective medium model, the volume of water adsorbed by the material is calculated. EPA becomes an effective method for characterization of porosity volume, pore size distribution (PSD), average pore size, cumulative surface area and Young's modulus of porous films. EPA is also suitable to evaluate the sealing of a porous layer. An example of study is carried on for TiO2 mesoporous prepared by Evaporation Induced Self-Assembly with various calcinations treatment. Plots results are characteristic of mesoporous medium with well defined pore dimensions. Upon calcinations, EP-A allows to follow a significant pores enlargement from 3 to 10 nm. In this paper, the instrument as well as TiO2 porous thin film study will be presented.

Crystalline TiO2 (Anatase configuration) thin films is widely used in the photocatalysis and photovoltaic industries ((self cleaning surface and renewable energies for example). The synthesis of these films is obtained from a dispersed solution of molecular poorly condensed species using Sol-Gel and liquid deposition processes. It allows the introduction of organic molecules (porogenes) inside inorganic network to create what is called hybrid materials. Spectroscopic ellipsometry is the technique of choice to characterize thickness and refractive indices of such thin layers. The adsorption of water at atmospheric pressure within the pores, modifies the refractive index of the layer. The change in refractive index induced by the introduction of water is measured by ellipsometry. A Lorentz Lorenz effective medium model is used to calculate the volume of water adsorbed by the material. Atmospheric Ellipsometric porosimetry (EPA) measurements become an effective method for characterization of porosity, pore size distribution (PSD), average pore size, Cumulative surface area and Young's modulus of porous films. EP is also suitable to evaluate the sealing of a porous layer.. EP evaluates the change in refractive index due to the penetration of the solvent through the sealing layer into the porous layer. In this paper, the instrument as well as some examples will be presented the abstract two lines below author names and addresses.

The electromagnetic field distribution inside multilayer organic solar cells is simulated and optimized. The relative importance of optical, electrical and morphological properties of the different thin films is discussed.

We have investigated the short-circuit current density of organic solar cells based on poly (3-hexylthiophene)(P3HT)/6,6-phenyl C61-butyric acid methyl ester (PCBM) blend. In order to model charge collection efficiencies with respect to short circuit density in such blends, a full optical modeling of the cell is performed. From the distribution of the electromagnetic field, we compute the rate of exciton generation. This exciton generation rate is used as input in the transport equations of holes and electrons. Charge densities at steady state are obtained as solutions are used for computing short-circuit current densities generated in the cell. The dependence of short-circuit current densities versus the thickness of the blend is analyzed and compared with our experimental data and with data extracted from the literature.

Spectroscopic Ellipsometry is the technique of choice to characterize thickness and refractive indices of thin layers. Atmospheric Ellipsometry Porosimetry (EPA) measures the change of the optical properties and thickness of the materials during adsorption and desorption of wet air at atmospheric pressure. Concentration of humidity changes at each step of measurement from dry air to saturated air. This non contact and non destructive technique is an effective and unique method to characterize porosity, pore size distribution (PSD) and Young modulus of thin porous films. It does not require to scratch the film, does not need low temperature or low pressure.Detailed description of the technique will be exposed in the paper and several meso-porous films (with pore size larger than 1nm) using the Kelvin formalism will be presented. The porosity of the layer ranges from few percent up to 40%. As it is an optical method, it is non contact, non destructive, fast (down to 15 minutes) and room temperature method. It does require low pressure or any preparation of sample. Solid oxide fuel cell is an electrochemical device that converts the chemical energy in fuels into electrical energy by exploiting the natural tendency of oxygen and hydrogen to react. The cell is constructed with two porous electrodes, which sandwich an electrolyte. Selection of materials for the individual components presents the most significant challenges in this technology. Each material must possess the correct chemical, electrical and structural properties to perform its function in the cell. Yttria stabilized Zirconia, (YSZ) is a suitable material for two of the components in this system: the anode and the electrolyte, where its morphology is notably different for each component. Using EPA technique, it becomes possible to characterize in term of porosity and pore size distribution the morphology of both components made by YSZ. We will show the characterization of material in thin film with different porosity and pore size distribution. Graded porosity versus depth could be also demonstrated and will be shown for the first time on such material.

VUV spectroscopic ellipsometry down to 135nm is applied to the characterization of HfO2, Al2O3 and HfAlOx thin layers prepared by atomic layer chemical vapor deposition. It is shown that the absorption of the different kinds of layers becomes important in the VUV range. So, the optical contrast is enhanced and more precise structural information can be deduced and in particular the composition and crystalline character of the HfAlOx layers. Results are compared to those provided by other experimental techniques like x-ray reflection (XRR) and high resolution transmission electron microscopy (HRTEM).