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Simulation of atomic redistribution in Geâ€"Sbâ€"Te (GST)-based memory cells during SET/RESET cycling is needed in order to understand GST memory cell failure and to design improved non-volatile memories. However, this type of atomic scale simulations is extremely challenging. In this work, we propose to use a simplified GST system in order to catch the basics of atomic redistribution in Ge-rich GST (GrGST) films using atomistic kinetic Monte Carlo simulations. Comparison between experiments and simulations shows good agreements regarding the influence of Ge excess on GrGST crystallization, as well as concerning the GST growth kinetic in GrGST films, suggesting the crystallized GST ternary compound to be off-stoichiometric. According to the simulation of atomic redistribution in GrGST films during SET/RESET cycling, the film microstructure stabilized during cycling is significantly dependent of the GST ternary phase stoichiometry. The use of amorphous layers exhibiting the GST ternary phase stoichiometry placed at the bottom or at the top of the GrGST layer is shown to be a way of controlling the microstructure evolution of the film during cycling. The significant evolution of the local composition in the amorphous solution during cycling suggests a non-negligible variation of the crystallization temperature with operation time. [ABSTRACT FROM AUTHOR]

In this paper we highlight the existence of tensile stress in heavily arsenic-doped epitaxial silicon (Si:As) prepared by low pressure chemical vapor deposition. Despite the large size of As atoms compared to Si ones, we demonstrate with x-ray diffraction and convergent electron beam diffraction that the heavily doped epitaxial layers show a tetragonal lattice with a reduced out of plane parameter. Using positron annihilation spectroscopy, we highlight the formation of arsenic-vacancies defects during the growth. We show that the tensile strain is related to this type of defects involving inactive As atoms and not to the As active concentration. [ABSTRACT FROM AUTHOR]

We describe an x-ray microprobe measurement of selectively grown heteroepitaxial Si[sub 1-x]Ge[sub x] on Si. The experiment was conducted at the European Synchrotron Radiation Facility of Grenoble at the ID13 Microfocus beamline. The Si[sub 1-x]Ge[sub x] layers were deposited by a standard chemical vapor deposition process on patterned 200 mm wafers of monocrystalline Si substrate. The uniformity of the pseudomorphic layers, in terms of Ge content and thickness, is evaluated by double crystal x-ray diffraction with the use of a novel microgoniometer and with a spatial resolution of ∼5 × 7.5 µm². The results show the good uniformity of the SiGe layers and indicate the possibility of evaluating the strain fields near the shallow trench isolation structures. [ABSTRACT FROM AUTHOR]

Presents a study which examined quantitavely by a silicon dioxide-encapsulated silicon-on-silica structure the supercooling of silicon. Experiment; Results; Discussion; Conclusion.

Investigates a periodic heat-sink structure in lamp recrystallization of thin polycrystalline silicon films deposited on oxidized wafers. Investigation on the effect of the scan speed; Importance of the in-plan orientation relative to the scan direction in the occurrence of defects inside the thin silicon films on insulator stripes; Mechanisms which can decrease the silicon melting temperature.

Presents a study that performed nondestructive characterization of a large variety of silicon-on-insulator (SOI) structures by means of infrared spectroscopic ellipsometry (IRSE). Applicability of IRSE for the characterization of SOI; Additional information provided by IRSE spectra concerning the SOI structure; Advantages of the IRSE method as compared to classical optical techniques using visible light.

Presents information on a study which performed zone melting recrystallization of polycrystalline silicon films on oxidized wafers using linear strip heaters to obtain good quality silicon-on-insulator (SOI) films. Elimination of the effects related to variations of the in-plane crystallographic orientation; Information on partial meltings carried out using a SOI sample; Recrystallizations carried out in the lamp system.

Presents information on a study which used capacitance-voltage technique to perform a comparison between various silicon epitaxial layer structures grown by the limited reaction process using silane, disilane or dichlorosilane, diluted in hydrogen. Layer growth; Measurement of the residual doping concentration of the epitaxial layers; Description of the capacitance-voltage technique; Quantitative analysis and discussion.

Presents a study that measured the epitaxial growth rate of silicon in the disilane/hydrogen system for different experimental conditions in a rapid thermal processing-low-pressure chemical vapor deposition reactor. Information on the measured activation energy; Growth rate dependence on disilane or hydrogen partial pressures; Proposed model for the decomposition of the disilane molecule in the torr pressure regime.