Papers by Keyword: RBS

Abstract: Monolayer (ML) thick Ge deposition on (100) Si substrates by molecular beam epitaxy (MBE) technique using an ultrathin SiO2 interlayer has been studied by ion beam analysis and photoluminescence (PL). The dependence of the Ge layer growth mode on the amount of the deposited Ge and the SiO2 thickness has been investigated. Atomic hydrogen treatment has been performed in order to passivate non-radiative recombination channels and to enhance the PL intensity. We conclude the formation of Ge quantum dots for the sample with the thickest Ge and SiO2 layers (9 Å and 1 ML, respectively).

Abstract: Diamond-like carbon (DLC) films were deposited on stainless steel disc substrates by plasma immersion ion implantation and deposition (PIII&D) technique. Ar, CH4 and C2H2 gas were used as the working gases and discharged by radio frequency at 13.56 MHz. During the implantation and deposition process the plasma discharge was monitored by optical emission spectroscopy in order to analyze the state of the chemical species presented in the plasma. Ion implantation (Vbias = -20 kV and –10 kV) process served to produce a graded interface between the DLC films and the substrate material. Deposition (Vbias = -5 kV) process using a gas mixture of C2H2/Ar with a ratio of 1:1. The structure information of the DLC films was evaluated by Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The composition of the DLC films and the thickness was measured by Rutherford backscattering spectrometry (RBS). The tribological properties were analyzed using a pin-on-disk tribometer and a microhardness tester, respectively. It was found that the DLC film was 0.8 μm thick with a hardness of 2.54 GPa and had good friction properties. Raman spectra appeared as G-band and D-band centered at 1550 cm-1 and 1418 cm-1, respectively. FTIR analysis observed the sp3 C=H2 asymmetric and sp2 C=C bond at 2928.73 cm-1 and 1667.10 cm-1 peak.

Abstract: In this work we present results of Si/SiO2/SiON/SiO2 waveguides fabricated by means of ECR-PECVD. In order to change refraction index and simultaneously to reduce losses related with hydrogen, we have used N2 as precursor gas for controlling the nitrogen to oxygen relation present in the samples. The composition of the samples were carefully controlled by RBS and ERDA analysis. The refractive index and thickness were measured by using a prisma coupler method at a wavelength of 632.8 nm.

Abstract: The microstructural characterization of r.f. magnetron sputtered ZnO thin films deposited on 6H-SiC is presented with a comprehensive investigation of their properties as a function of annealing temperature and film thickness. These structures, with some modifications, are utilised as Schottky diode hydrogen gas sensors and Surface Acoustic Wave (SAW) devices.