Search

Atomic force microscopy (AFM) and scanning electron microscopy (SEM) have been used to quantify bone morphology during post-injury ossification in rate tibiae and characterize the differences induced by laser photostimulation compared with the naturally-occurring regenerative process. SEM and AFM images of the cortical bone at the recovery stages of 8 and 15 days after the injury are discussed.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Due to its simplicity polarization reflectometry technique have some advantages over the ellipsometric methods. We demonstrate this claim in the threefold manner suggesting three novel polarization reflectometry methods for the determination of an optical anisotropy. The first method is based on the measurement of s- and p- polarized light reflectances under near normal or grazing angles (or both) and of the Brewster angle. It may be applied to any uniaxially anisotropic medium. The second method is based on the use of the Azzam Universal Relationship (AUR) between the Fresnel s- and p- reflection coefficients. For a flat surface and an isotropic medium, the Azzam combination of coefficients becomes zero and thus independent of the incidence angle. Finally, for those cases in which the anisotropy of the material of a film deposited on an isotropic substrate is itself of interest a third Interference Method (IM) is suggested. This technique makes use of the different dependences of s- and p- polarized beam optical pathlength changes on the variation of the angle of incidence.

Diamond films have been deposited by hot-filament CVD on silicon using either a gas mixture of pure methane-hydrogen or a mixture of methane-hydrogen and carbon-tetrafluoride, for the study of the influenceof the fluorine radicals in the growth process. Raman spectra shows that the fluorine is effective in the etchingof non-diamond bonds since the corresponding Raman shift at 1550 cm1 due to sp2 was not observed in the films deposited with the CF1JCH4 gas mixture. Also the FTIR spectra of these films show a better transmittance in the range from 500 cm1 to 4000 cm1, and an apparent increase of the SiC layer thickness.Using the same thermodinamical conditions, with the CF1JCH4 gas mixture diamond films of high quality aredeposited at a higher growth rate. AFM measurements of the surface morphology indicates apparently thesame vertical roughness in both kinds of films but larger lateral coalescence in the films produced with CF4-content.1. INTRODUCTIONThe diamond transparency for photons from U.V. to I.R. range, combined with its high chemical inertness,high hardness and high thermal conductivity, make this material an ideal choice as protective coatings for

(Separation by IMplantation of OXygen). The SOS is the best-known technology, and has been employed by the industry insome niche markets, such as circuits for satellites and other special applications. The dissemination of the SOS technology islimited due to the high cost of the sapphire crystals and the contamination problems introduced in the diffusion furnaces bythe Al and other metallic impurities that are usually present in the sapphire. The SIMOX technology is under investigationas an alternative to SOS since it shows great potential for the elimination of contamination because the wafers contain onlySi and Si02. However, considerable investigation is needed to improve the SIMOX quality in order to compete with SOSand become a mature technology. The fabrication of SOT CMOS requires several ion implantation steps for the formation

Self-supporting bi-layer structures of Al/SiO2 thin-films has been investigated by a combination "in-situ" of Rapid Thermal Processing (RTP) and Transmission Electron Microscopy (TEM). We observed that the Al/Si02 mismatch results in high tensile stress that contribute to slower the kinectics of the Al nucleation. Practically there is no change of the Al morphology in the annealed samples even at temperatures up to 720 K. A metastable Al silicide was observed at temperatures around 370 K.

We have studied the mechanisms of the copper metallization on P-silicon wafers immersed in CuCN solutions, using photoelectrochemical measurements and optical/electron microscopy. In this process the electroplating is enhanced by the minority carries in illuminated areas of the silicon. cathode. The photo-selective deposition with high resolution have been obtained only on low doped P-silicon. The kinectics of the film growth is strongly dependent on the film thickness, and two mechanisms have been identified. Patterns of resolution of ~4 microns can be realized only with thickness bellow ~20 nm. Further investigation is needed for prevent the oxidation of the as-deposited film.

The rate of etching of Nb oxydes in plasmas of CF4-O2 and CF4-H2 gas mixtures has been investigated. The etch curves of the oxydes thermally grown at different temperatures ( 673 K - 1023 K ) and times ( 10 - 45 min ) show similar behavior as these of pure Nb films, but with etch rates a factor of 2-3 higher. Fluorine radicals seem to be the main reactants in the etch chemistry. The etching is anisotropic and the end-point detection can be accurately made by "in situ" laser interferometry.

A brief review of some important historical points on the origin of the Factories and the Industrial Revolution is presented with emphasis in the social problems related to the automation of the human labor. Until the World War I, the social changes provoked by the Industrial Revolution caused one division of the World in developed and underdeveloped countries. After that period, the less developed nations began their industrialization mainly through the Multinationals Corporations (MC). These enterprises were very important to the production and exportation of utilities and manufactures in general, mainly in those products which required intensive and direct human labor. At present time, with the pervasiveness of microelectronics in the automation, this age seems to reaching an end because all continous processes in industry tend economicaly toward total automation. This fact will cause a retraction in long-term investments and, beyond massive unemployment, there is a tendency for these MC industries to return to their original countries. The most promising alternative to avoid these events, and perhaps the unique, is to incentive an autonomous development in areas of high technology, as for instance, the microelectronics itself.