Papers by Keyword: Micro Raman

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Authors: W.C. Mitchel, J. Brown, D. Buckanan, R. Bertke, K. Malalingham, F. Orazio, P. Pirouz, Huang-Ju R. Tseng, Uma B. Ramabadran, Bahram Roughani
Authors: L. Sangaletti, L.E. Depero, B. Allieri, S. Groppelli, G. Sberveglieri
Authors: Joana Catarina Madaleno, Luiz Pereira
Abstract: In this work we present an equipotential surface map with a resolution higher than 100 nm, resulting from conductive atomic force microscopy (AFM). The images, obtained in polycrystalline MPCVD (Microwave Plasma Assisted Chemical Vapor Deposition) diamond devices, are clearly structure dependent. Diamond and non-diamond phases were identified by micro-Raman spectroscopy and correlated with the electrical conduction map. The application of the non-homogeneous contact theory lead to the extraction of two Schottky Barrier Heights (SBH), one close to 0.6 V with dispersion ~ 0.1 V, attributed to the diamond / metal interface, and the other close to 0.4 V with dispersion ~ 0.04 V, due to the non-diamond phases / metal interface. The diamond / non-diamond phase ratio is about 85:15, taken from the micro-Raman spectra. Combining these results with the electrical conduction map, a general model to predict the macroscopic electrical behavior of polycrystalline diamond based devices is proposed.
Authors: K. Chourou, Mikhail Anikin, Jean Marie Bluet, V. Lauer, Gérard Guillot, Jean Camassel, Sandrine Juillaguet, O. Chaix-Pluchery, Michel Pons, R. Pons
Authors: A. Tabata, R. Enderlein, A.P. Lima, J.R. Leite, V. Lemos, S. Kaiser, D. Schikora, B. Schöttker, U. Köhler, K. Lischka
Authors: Xing Fang Liu, Guo Sheng Sun, Jin Min Li, Yong Mei Zhao, J.Y. Li, L. Wang, Wan Shun Zhao, M.C. Luo, Yi Ping Zeng
Abstract: Three types of defects, namely defect I, defect II, defect III, in the 4H-SiC homoepilayer were investigated by micro-raman scattering measurement. These defects all originate from a certain core and are composed of (I) a wavy tail region, (II) two long tails, the so called comet and (III) three plaits. It was found that there are 3C-SiC inclusions in the cores of defect II and defect III and the shape of inclusion determines the type of defect II or defect III. If the core contains a triangle-shaped inclusion, the defect III would be formed; otherwise, the defect II was formed. No inclusion was observed in the core of the defect I. The mechanisms of these defects are discussed.
Authors: L.E. Depero, L. Sangaletti, B. Allieri, F. Pioselli, C. Casale, M. Notaro
Authors: Sandrine Juillaguet, Carole Balloud, Julien Pernot, C. Sartel, Véronique Soulière, Jean Camassel, Yves Monteil
Authors: M. Pandiaraman, N. Soundararajan, R. Ganesan
Abstract: Silver telluride (Ag2Te), I-VI semiconductor compound with potential applications in various advanced fields. Ag2Te nano films of thickness between 16 nm and 145 nm prepared by thermal evaporation technique at high vacuum better than 2x105 mbar. These films are found to exhibit polycrystalline nature with monoclinic structure from their XRD studies. The average particle size of these films are found to be around 24 nm using the Debye-Scherrer’s formula From AFM measurements, the average particle size is around 24 nm. The emission spectra of these films were recorded and analysed to determine its optical band gap. Optical band gap of Ag2Te varies from 1.6 eV to 1.8 eV with respect to their corresponding thicknesses of films.
Authors: Richard Nader, Jörg Pezoldt
Abstract: To improve the quality of AlN layer deposit on SiC/Si, different Ge amounts (0.25, 0.5, 1, 2ML) were deposited before the carbonization process at the silicon substrate in order to reduce the lattice parameters mismatch between Si and SiC grown layers. The residual stress of the hexagonal AlN layers derives from the phonon frequency shifts of the E1(TO) phonon mode. The crystalline quality of the AlN layer is correlated to and investigated by the full width of the half maximum (FWHM) and the intensity of E1(TO) mode of the 2H-AlN. Best crystalline quality and lower stress value are found in the case where 1ML of Ge amount is predeposited. The E1(TO) mode phonon frequency shifts-down by 3 cm-1/GPa with respect to an unstrained layer.
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