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European Vacuum Conference (EVC 5) / International Conference on Thin Films (ICTF 10) (5th / 10th. 1996. Salamanca, Spain). (C) Elsevier Science SA., The influence of the gas flow ratio (R) (O-2/SiH4 and N-2/SiH4) and the deposition temperature on the physical properties of SiOy and SiNx:H thin films deposited by the ECR-CVD method is analyzed. Two deposition regimes limited by R = 1, are found for SiOy films. At R < 1, films are very Si-rich in nature, with [O]/[Si] ratios as low as 0.55. At R > 1, the [O]/[Si] ratio varies between 1.69 and 1.88 and the full width at half maximum of the Si-O stretching peak is almost kept constant at 90 cm(-1). The effect of increasing substrate temperatures is mainly to promote a nearest stoichiometric character of the films. The two deposition regimes described agree with the optical diagnosis of the discharge, that present Si related species in those created at R < 1, and OH and O-2(+) species in those created at R > I. A similar trend is observed for the deposition of SiNx:H films, for which the limiting gas flow ratio is also R = I. At R < 1, the films are very Si-rich (x less than or equal to 0.38), meanwhile at R > 1, the composition corresponds to near stoichiometric and N-rich films (x = 0.91-1.49). The main effect of the substrate temperature is to reduce the hydrogen content of the films. Both SiOy and SINx:H films are used in Si-based MIS structures, for those the minimum density of interface states is 3 X 10(11) cm(-2) eV(-1)., Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

International Vacuum Congress (14. 1999. Birmingham, Inglaterra )/ International Conference on Solid Surfaces (10. 1999. Birmingham, Inglaterra) / International Conference on Nanometre-Scale Science and Technology (5. 1999. Birmingham, Inglaterra) / International Conference on Quantitative Surface Analysis. (10. 1999. Birmingham,Inglaterra). © EIsevier Science SA., We have analyzed the influence of rapid thermal annealing (from 300 to 1050 degrees C) on the optical properties of a-SiN(x):H. Three compositions were investigated: x = 0.97, x = 1.43 and x = 1.55. Two different behaviors are observed depending on whether the as-grown nitrogen to silicon ratio of the samples is above or below the percolation threshold (x = 1.1) of Si-Si bonds, in the matrix of silicon nitride. The samples with x: = 1.43 and 1.55 experience an increase of the Tauc coefficient (B) and a decrease of the Urbach parameter (E(0)) at low annealing temperatures. while at high temperatures the trend is inverted. On the contrary, the samples with x = 0.97 show a slight and continuous increase of B and a similar decrease of E(0). The different behavior of the films with x < 1.1 is explained by the percolation of the Si-Si bonds, which maintains the order of the structure at high annealing temperatures, preventing the inversion of the trends of B and E(0)., Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

© i996 Elsevier Science S.A.. The authors wish to tank Dr J.J. Schermer and Dr G.Jansen for the loan of the samples. Mr A.J. Fernandes is acknowledged for his help in the Raman measurements. This work has been partially supported by DGICYT project numbers PB93-1256 and HP95-98B., Flame grown diamond films on a molibdenium substrate are characterised by cathodoluminescence (CL), photoluminescence (PL), micro-Raman and scanning electron microscopy in the emissive mode. Different crystal habit regions grow with an annular symmetry. A correlation between morphology, CL, PL and Raman measurements is obtained for each region. The influence of the growth parameters is discussed., DGICYT (Spain), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© Elsevier Science Ireland Ltd. The authors like to thank J. Messarosch, G. Fehlauer, H. Baumgärtner, F. Kaesen, H. Geiger, V.R. Rao and T. Pompl for their assistance in electrical measurements, sample preparation and fruitful discussions. The expertise of J. Ramm, E. Beck and R. Slepicka of Balzers AG is greatfully acknowledged. This work was supported by the BMBF under grant no. BA-672. One of the authors, A. Strass, likes to thank the German Academic Exchange Service (DAAD) for financial assistance during his scientific stay at the Universidad de Chile., We developed and tested three MBE-compatible processes for the deposition of high-quality low-temperature silicon oxides and oxynitrides in the ultra high vacuum at substrate temperatures between room temperature and 500 degrees C, gas enhanced evaporation (GEE), plasma enhanced evaporation (PEE) and plasma enhanced oxidation (PEO). The deposited layers were thoroughly investigated and compared with respect to their electrical, optical and stoichiometrical properties by means of ellipsometry, mechanical profilometry, Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), Rutherford backscattering (RBS), Fourier transform infrared ((FTIR) spectroscopy, and by electrical measurements (I-V, C-V) on MOS structures. A model of the growth mechanism for each of the processes is suggested., German BMBF, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

International Vacuum Congress (14. 1999. Birmingham, Inglaterra) / International Conference on Solid Surfaces (10. 1999. Birmingham, Inglaterra) / International Conference on Nanometre-Scale Science and Technology (5. 1999. Birmingham, Inglaterra) / International Conference on Quantitative Surface Analysis (10. 1999. Birmingham, Inglaterra). © Elsevier Science SA., Silicon oxynitride films were deposited at room temperature using the ECR-PECVD technique. Precursor gases were O(2), N(2) and SiH(4). The composition of the films can be controlled by regulating the gases flow ratio. R = (O(2) + N(2))/SiH(4) and R' = O(2)/SiH(4) have proved to be the key deposition parameters. FTIR spectroscopy, AES and ellipsometric measurements were performed in order to characterise the films. A single Si-O/Si-N stretching band is observed in the FTIR spectrum for all compositions, indicating single-phase homogeneous SiO(x)N(y) films. FWHM of the stretching band shows a maximum for the composition corresponding to the same number of Si-O and Si-N bonds. Samples cover the whole composition range from silicon nitride to silicon oxide including nitrogen-rich films, even though the gas flow ratio R " = N(2)/O(2) during deposition was small (from R " = 1.0 for SiO(1.9)N(0.04) to R " I = 6.7 for SiO(0.26)N(1.2)). Silicon oxide composition samples (SiO(2.0)) show essentially the same TR features as the thermal oxide: Si-O stretching band located at 1072 cm(-1), with a FWHM of 96 cm(-1) and a shoulder/peak ratio of 0.30, while nitrogen-rich samples (SiO(0.26)N(1.2)) show a total bonded hydrogen content below 2 x 10(22) cm(-3)., Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

© 1999 Elsevier Science S.A. This work was partially supported by DGICYT (Project No. PB93-1256)., Diamond and diamond-like films grown by the torch flame method have been analysed by different techniques, namely scanning electron microscopy, Raman spectroscopy, electron paramagnetic resonance and catholuminescence microscopy, in order to investigate the main structural features of the different habits present in the films. A correlation between the observed crystal habits, the defect structure and the formation of diamond and/or diamond-like phases has been established. This enables a general quality assessment of the deposits and their correlation with some features usually observed in carbon films, DGICYT (Spain), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2000 Elsevier Science S.A. All rights reserved. European Conference on Diamond, Diamond-Like Materials, Nitrides and Silicon Carbide (10. 199. Praga. Republica Checa). The authors wish to thank Dr. Qi Hua Fan and Mr. A.J. Fernandes for the growth facilities., The properties of microelectrical conduction in microwave plasma assisted chemical vapour deposition (MPCVD) diamond films were investigated using an atomic force microscopy probe, giving a morphological map of the electrical conduction with a spatial resolution better than 500 nm. Also, a cathodoluminescence map with a spatial resolution of about 1 mu m was obtained, giving the possibility of correlating the defects involved in the different carrier transport phenomena. Using micro-Raman analysis several bands could be identified. It is found that the defects responsible for the cathodoluminescence (CL) blue band are responsible for the major part of the electrical conduction in diamond films, while the defects localised in < 111 > surfaces, responsible for the green CL emission, could be involved in a less conductive process., Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub