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Presents a study which compared two processes of ultraviolet laser incorporation of dopants into silicon. Method of the study; Results and discussion; Conclusion.

Abstract. Diamond-like carbon (DLC) films have been grown on Si substrates at ambient temperature by the pulsed-laser ablation technique, using pulses of different durations both in the nano- and picosecond ranges and at various energy fluences. The stability of these films was investigated as a function of thermal anneals performed in UHV conditions up to 1273 K. Their physico-chemical properties have been characterized by different techniques including X-ray photoemission, Auger electron and electron-energy-loss spectroscopies, Raman scattering, spectroscopic ellipsometry and atomic-force microscopy. The thermal stability of the films has been demonstrated to be related to their initial structural (sp[sup 3]/sp[sup 2] ratio) and chemical (contaminant) properties. DLC layers prepared under optimized conditions have been found to show a very good thermal stability up to 900 K. [ABSTRACT FROM AUTHOR]

Abstract. In this work, the excimer-laser-induced crystallization of a-Si films on SiO[sub 2] was investigated using a long-pulse-duration (200 ns) XeCl source. The microstructural analysis of the laser-irradiated area, for incident energy densities comprised between the thresholds corresponding to the surface and full melting, respectively, of the Si layer, was performed by scanning electron microscopy and Raman spectroscopy. A super-lateral-growth regime was evidenced quite comparable to that which occurs when classical excimer laser pulses of short duration (is approximately equal to 20 ns) are used. A numerical simulation of the surface melt dynamics was also performed and compared to the experimental observations. [ABSTRACT FROM AUTHOR]

We have investigated laser-induced oxidation of ion-implanted Si using a repetitively pulsed ArF laser, working at low-energy density (100–500 mJ/cm2). Oxidation is observed at energy densities between the melt threshold and that required for epitaxial recrystallization of the amorphous layer. At these energy densities, oxidation is not observed on virgin silicon. The factors that influence the oxidation process are discussed. [ABSTRACT FROM AUTHOR]

Formation of epitaxial Si1-yCy substitutional alloy layers on monocrystalline silicon surfaces with y≊1 at. % is reported. The preparation method was carbon ion implantation, followed by KrF excimer laser annealing. Results of Rutherford backscattering (RBS), secondary ion mass spectrometry (SIMS) and infrared absorption analyses are compared. The authors concluded that, up to ∼1 at. % carbon content, the dominant process is nonequilibrium trapping of carbon in substitutional lattice sites upon fast resolidification. Above this concentration the complex carbon redistribution processes are influenced by silicon carbide precipitation in the melt and segregation effects in the near-surface region. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Interference microscopy is a useful analytical tool for studying the surface morphology of semiconductors. Surface roughness from nanometres to many microns can be measured rapidly and non-destructively, making it possible to analyse fragile materials. Blue–violet illumination gives submicron lateral resolution and a large field size can be achieved using sample scanning and image ‘stitching’. Some of these new developments in interference microscopy are presented and applied to the optimisation of laser annealing of a-Si layers for flat panel displays, and to the analysis of surface morphology of HgI2 and PbI2 for nuclear detectors. [Copyright &y& Elsevier]

Abstract: The purpose of this work is to determine the optimal parameters required to crystallize thin amorphous silicon films on glass substrate with a continuous wave (CW) laser diode (λ =808nm), using a numerical model developed in COMSOL Multiphysics. The numerical simulation of the laser crystallization process takes into account the solid–liquid phase change and the difference between the melting temperature of amorphous (Tma-Si =1420K) and that of crystalline silicon (Tmc-Si =1690K). We have varied the main parameters controlling the crystallization process, namely the power and the scan speed of the laser beam. Furthermore the initial temperature as well as the thickness of the a-Si:H layer were also taken as a parameter to optimize the process. We have determined the melting, crystallization and ablation energy threshold versus the different operational parameters. [Copyright &y& Elsevier]