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Articles you may be interested inStudy of the annealing kinetic effect and implantation energy on phosphorus-implanted silicon wafers using spectroscopic ellipsometry J. Appl. Phys. 99, 123514 (2006); 10.1063/1.2207688Model-dielectric-function analysis of ion-implanted Si(100) wafers Crystalline to amorphous transition and band structure evolution in ion-damaged silicon studied by spectroscopic ellipsometry Damage created by ion implantation into single crystalline silicon was characterized with an optical model based on the coupled half-Gaussian model developed by Fried et al ͓J. Appl. Phys. 71, 2835 ͑1992͔͒. In the improved optical model the damage profile was described by sublayers with thicknesses inversely proportional to the slope of the profile. This method allows a better resolution at the quickly changing parts of the profile, and a better approximation of the Gaussian profile with the same number of sublayers. A fitting procedure, which we call ''multipoint random search,'' was applied to minimize the probability of getting in a local minimum. The capabilities of our method were demonstrated for amorphizing doses using different ions and energies. The improved fit quality and the correlation with results of backscattering spectrometry basically supported the optical model.

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Semiconducting CrSi 2 nanocrystallites (NCs) were grown by reactive deposition epitaxy. The NCs were covered by 100 nm of epitaxial silicon. Their structure, morphology and optical properties were investigated by transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet photoelectron spectroscopy (UPS) and optical reflectance spectroscopy (ORS). The preservation of the CrSi 2 phase has been justified by UPS, by ORS, and by TEM measurements. The distribution of Cr was investigated by Rutherford backscattering (RBS). The electrically active defects were investigated by deep level transient spectroscopy (DLTS). The crystal structure of the NCs nucleated near the deposition depth is identified by high-resolution TEM as hexagonal CrSi 2 . Energy filtered TEM shows that most of the Cr is localized in the threedimensional (3D) NCs. RBS shows that the concentration of Cr is appropriate for the deposited quantity. In the 0.1 nm Cr sample most of the Cr is localized near the surface; in the 0.6 nm Cr sample the concentration increases at the depth of Cr deposition, while in the 1.5 nm Cr sample the excess Cr is localized near the deposition depth. DLTS Arrhenius plots give activation energies of the defects appropriate for Cr contamination, however these defects may be related to the CrSi 2 NCs.

Bulk single‐crystal CdTe, sputter‐deposited polycrystalline CdTe films of about 2.5 micron thickness, and single‐crystal Si (c‐Si) have been ion implanted using 350 keV Xe at fluences ranging from 1×1013 to 16×1013 cm–2 so as to create disorder in a controlled way from fully single‐crystalline to fully amorphous material. The general purpose of the investigations is to seek a parameterization of the critical point structures and establish a database for fitting the optical properties of CdTe films having different unknown grain sizes whereby the grain size will be described in terms of an effective defect density. The polycrystalline CdTe samples were magnetron sputtered onto c‐Si followed by CdCl2 and Br2‐methanol treatment to improve properties in terms of grain size and surface smoothness, respectively. The fluences for use in the ion implantation of CdTe were estimated using the SRIM (Stopping and Range of Ions in Matter) software, and cross‐checked by simultaneous implantation of bulk c‐Si samples. The optical properties were characterized by second derivative analysis and by a generalized critical point model. Although the damage created by 350 keV Xe in the simultaneously implanted c‐Si samples, as measured by both spectroscopic ellipsometry and Rutherford backscattering/ channeling spectrometry (RBS/C), agrees well with the expectations based on the SRIM simulation, the damage created in CdTe remains at a very low level even for doses several times higher than the amorphization level estimated by simulation. The character of the dechanneling of the RBS/C spectra indicates extended defects (presumably dislocation loops). This effect was similar in both single‐crystal and thin film polycrystalline CdTe, although less pronounced in thin film samples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)